Codex, Claude Code and Google Antigravity now sell three different bets on how a coding agent should work, and the price spread runs from a $0 Antigravity free plan to a $500 ChatGPT Pro tier. As of October 29, 2026, each product runs on a freshly updated model line. OpenAI leans on GPT-6 Astra, GPT-6.1 Sol and GPT-6.1 Terra, Anthropic on Claude Opus 5.5, and Google on Gemini 4 Argon.
The number most buyers need first is the API rate. Claude Opus 5.5 lists at $4 per million input tokens and $20 per million output tokens on Anthropic’s pricing page, while Gemini 4 Argon costs half that ($2 and $10) only until November 30. This codex vs claude code comparison adds Antigravity because Google moved its own agentic coding bet there, and because all three vendors changed prices, limits or model lineups in the past 30 days.
A head-to-head on Claude Code versus Codex cost per task already covers one slice of this market. What it could not cover is the calendar. Between now and December 1, three dated changes (a reported Codex Pro limit cut, a reported removal of Claude models from some free Antigravity accounts, and the Argon price step) will shift the math for every team on this page.
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Codex vs Claude Code vs Antigravity: The Short Answer
Pick Claude Code with Opus 5.5 if you want the strongest published merge-readiness score and you accept a $20 to $200 monthly subscription ladder. Pick Codex if your company already pays for ChatGPT Business or Enterprise and you want parallel agents, a macOS app and a fast tier. Pick Antigravity if you want to start at $0, mix Gemini with Claude inside one editor, and can live with quota rules that Google rewrote in May.
Here is the compressed version of what the current data supports.
- Quality claim with a number: Anthropic reports that Opus 5.5 scores 54.6% on FrontierCode at default (medium) effort, against 53.3% for the best GPT-6 Astra result, at about a fifth of the cost per task. That is a vendor-run test, so treat it as a strong hint and not a verdict.
- Cheapest way in: Antigravity starts at $0 a month on a Free plan. Claude Code starts at $20 with Pro. Codex rides on ChatGPT plans, with the verified Pro tiers at $100, $200 and $500.
- Fastest tier: OpenAI says GPT-6 Astra Ultrafast generates up to 300 tokens per second in Codex, and it sits on Pro 500 and Enterprise. Anthropic’s Opus 5.5 fast mode runs up to 2.5 times faster at $8 and $40 per million tokens.
- Biggest pricing risk: Argon’s $2 and $10 rate doubles to $4 and $20 on December 1, which erases Google’s token-price edge over Opus 5.5.
Nothing here is a clean sweep. The honest answer depends on whether your constraint is dollars, merge quality, seat management or editor lock-in. The sections below sort each constraint into a pick, and the verdict near the end puts a number on it.
What Changed in the Last 30 Days
Coding-agent pricing pages went stale faster in October 2026 than in any month this year. Anyone who read a comparison written in September is working from a different product. The dated changes below come from vendor release notes, vendor announcements and Google’s Antigravity blog.
OpenAI and Codex
- GPT-6.1 Sol was announced on September 29 as an upgrade for agentic coding and computer use. Plus, Pro, Business, Enterprise and Edu users can run it in Codex.
- Pro 500 arrived at $500 a month on September 29, and Pro 200 went back on sale to new subscribers.
- OpenAI removed GPT-5.5 from ChatGPT, ChatGPT Work and Codex on October 14. The API was not affected.
- On October 21, OpenAI said its frontier models and Codex agentic workflows are coming to Google Cloud’s Model Garden. The same announcement said OpenAI models would soon appear inside Google Antigravity and the Gemini Agent. That move is covered in more depth in a piece on OpenAI models reaching Google Cloud.
- GPT-6.1 Terra began rolling out in Codex on October 26 for visual reasoning and computer use, and OpenAI shipped a Codex macOS app on October 28 as a command center for running several agents in parallel.
Anthropic and Claude Code
- Claude Opus 5.5 shipped as the first model in the Claude 5.5 family. Anthropic describes it as leading in agentic coding and costing 40% less to run than Opus 5 on typical workloads.
- Claude Haiku 5.5 followed on October 7 as the fast, cheap small model for subagents and browser use. Anthropic also announced monthly Claude Platform credits for Max and Team subscribers that day.
- Sonnet 5.5 rounded out the family, with Anthropic claiming it runs more than 30% faster than Sonnet 5 and costs up to 30% less for most work.
Google and Antigravity
- Google stopped selling new Gemini Code Assist Standard and Enterprise subscriptions on October 9, and Antigravity became the successor path for agentic coding.
- Gemini 4 Argon launched on October 13 and landed in Antigravity the same day, first for Google AI Ultra subscribers and then for paid Pro subscribers.
- On October 28, Google announced Gemini 4 Carbon as a stronger model that builds on Argon. Google’s materials do not yet establish that Carbon is generally available in Antigravity, so this article compares Argon.
Dated changes still ahead
- A tracker at apidog reports a Codex Pro usage reduction on October 30. OpenAI’s release notes did not confirm the details at the time of writing.
- An Enjoy Agentic Industries post reports that Antigravity will pull Claude models from some free, Google AI Plus and trial accounts on November 2.
- Argon’s introductory price ends November 30 and the standard rate starts December 1.
Treat the first two items as reported and recheck the vendor pages before you commit a team budget to either tool.
Specs Comparison: Codex vs Claude Code vs Antigravity
The table below holds only facts confirmed on vendor pages or in multiple current sources. Where a vendor has not published a number, the cell says so.
| Spec | OpenAI Codex | Claude Code | Google Antigravity |
|---|---|---|---|
| Maker | OpenAI | Anthropic | |
| Top model in the tool | GPT-6 Astra (Ultrafast tier on Pro 500 and Enterprise) | Claude Opus 5.5 | Gemini 4 Argon |
| Lower-cost models | GPT-6.1 Sol, GPT-6.1 Terra, GPT-6 Luna | Sonnet 5.5, Haiku 5.5 | Gemini 3.8 Flash |
| Other vendors’ models inside the tool | OpenAI models only | Claude models only | Claude Opus 5.5 and Sonnet 5.5 (Thinking), GPT-OSS 120B |
| Surfaces | CLI, IDE extension, cloud, code review, macOS app, mobile preview | Terminal, IDE, desktop app | Desktop app, CLI, IDE extensions |
| Entry price | Included in eligible ChatGPT plans | Pro, $20 a month | Free plan, $0 a month |
| Top individual plan | Pro 500, $500 a month | Max 20x, $200 a month | Top Ultra tier, $200 a month |
| Flagship API price per 1M tokens (in / out) | Astra, $10 / $50 | Opus 5.5, $4 / $20 | Argon, $2 / $10 until Nov. 30, then $4 / $20 |
| Speed option | Astra Ultrafast, up to 300 tokens per second | Opus 5.5 fast mode, up to 2.5x faster, $8 / $40 | Not published |
| Cloud distribution | Google Cloud Model Garden (announced Oct. 21) | AWS, Google Cloud, Microsoft Azure | Google Cloud |
| Team route | Business, Enterprise, Edu plans | Team and Enterprise plans | Gemini Enterprise |
| Newest tool-level release | macOS app, Oct. 28 | Haiku 5.5, Oct. 7 | Argon in Antigravity, Oct. 13 |
| Status on Oct. 29, 2026 | Active | Active | Active |
Two rows deserve a second look. The row on other vendors’ models shows the clearest structural split. Antigravity is the only one of the three that lists a competitor’s flagship in its own model picker, and OpenAI said on October 21 that its models would soon join that picker too. Codex and Claude Code stay inside their maker’s model family.
The top individual plan row shows how close the premium ceilings sit. Claude’s Max 20x and Google’s top Ultra tier both land at $200 a month, while OpenAI added a $500 tier on top of its $200 one. That extra rung buys the Ultrafast speed tier and the highest included usage, not a different class of model.
The Models Behind Each Agent
An agent is only as good as the model it calls, and each vendor now sells several model sizes inside the same tool. The pairing logic matters as much as the flagship.
OpenAI: Astra for depth, Sol and Terra for volume
OpenAI positions GPT-6 Astra as its model for the hardest reasoning work, with support for Codex and computer-use workflows. It lists at $10 per million input tokens, $1 for cached input and $50 for output. GPT-6.1 Sol prices at $2, $0.10 and $10, and GPT-6.1 Terra at $1, $0.05 and $5. GPT-6 Luna, the efficient tier, sits at $0.10 and $0.50 for input and output.
That ladder gives Codex users a built-in cost lever. Route routine edits to Sol or Terra, keep Astra for the migrations and bug hunts that justify a 5x price premium over Sol. OpenAI’s pricing page also shows Free and Go plans without Sol access, and its documentation says Astra requires a recent Codex CLI build. One source puts that floor at version 0.153.0.
Anthropic: one family, three jobs
Anthropic’s own wording is blunt. Opus 5.5 targets long-running agentic coding and knowledge work, Sonnet 5.5 targets the balance of speed and intelligence, and Haiku 5.5 targets high-volume work such as summarization, subagents and browser use. Anthropic says Haiku 5.5 pairs with Opus 5.5 and Sonnet 5.5 as a coding subagent, which is the same routing idea OpenAI sells with Sol and Terra.
Opus 5.5 lists at $4 and $20 per million tokens, with cache reads at $0.20. Anthropic says it performs at the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5, helped by lower per-token prices and fewer tokens per task. Sonnet 5 holds at $2 and $10 after Anthropic made its introductory price permanent on August 10.
Google: Argon at a promotional price, Flash for the cheap lane
Google describes Gemini 4 Argon as built for complex software engineering, code migrations, long-horizon workflows and agentic coding. Antigravity’s model picker lists Argon at high reasoning effort, Gemini 3.8 Flash at medium, both Claude 5.5 Thinking variants and GPT-OSS 120B at medium. Cached input tokens cost 95% less than the base input rate.
The risk is the clock. Google says the introductory pricing ends November 30, 2026, after which rates become $4/$20 per million input/output tokens. At that point Argon is set to match Opus 5.5 per token, so the argument for Gemini has to come from quality, context or ecosystem rather than price.
Benchmarks: Three Vendor Sources and One Developer Survey
Independent, apples-to-apples coding benchmarks across Codex, Claude Code and Antigravity do not exist yet. Each vendor publishes its own numbers on its own harness. That is a limit worth stating plainly, because many comparisons paper over it with a single leaderboard row.
| Source | Metric | Result | Caveat |
|---|---|---|---|
| Anthropic (Opus 5.5 announcement) | FrontierCode, share of agent code changes that would be merged, default medium effort | Opus 5.5 at 54.6%, GPT-6 Astra’s top score 53.3%, at about a fifth of the cost per task | Vendor-run, and it compares against Astra, not Argon |
| OpenAI (pricing and model docs) | Output speed of Astra Ultrafast in Codex | Up to 300 tokens per second | Speed claim, not an accuracy score, and limited to Pro 500 and Enterprise |
| Google (Gemini 4 Carbon announcement) | SEC-bench Pro, autonomous discovery of real software vulnerabilities | Carbon at 88.2% | Security benchmark, and Carbon is not confirmed in Antigravity |
| Stack Overflow 2025 Developer Survey | AI agent adoption and perceived productivity | 31% of developers use AI agents, 69% of users agree productivity rose | Survey of opinion, taken before the GPT-6 and Claude 5.5 generations |
Anthropic’s page also charts CursorBench 4.0 and Terminal-Bench 4.0 as accuracy-versus-cost curves. The exact scores are not reproduced here because the current-facts sheet for this article does not hold them, and a rounded guess would add noise.
Google adds its own internal measurements. The company reports that Argon inside Antigravity lifted agentic code submissions by more than 35% and cut code rollbacks by nearly a third. It also says teams in Chrome, Ads and Search shipped 35% more code with 30% fewer errors in recent weeks. Google labels these as internal results, so they sit well below an independent benchmark in evidential weight.
A broader view of model rankings, including how leaderboards disagree, appears in this LLM leaderboard breakdown of Opus 5.5, GPT-6.1 Sol and Gemini 4 Argon. The practical advice for a coding-agent buyer is to run your own ten tickets through each tool before trusting any vendor chart.
What the survey adds
The Stack Overflow numbers frame the market even if they predate the newest models. The press release summarizing the survey reported that 31% of developers were currently using AI agents, while 17% planned to use them and 38% had no plans to adopt them. The main survey page added that among developers who had used AI agents at work, 69% agreed that the agents increased their productivity.
Those figures describe 2025. A year later, with GPT-6 and Claude 5.5 in production, the adoption base is almost certainly larger, but no 2026 survey in the current sources says by how much.
Subscription Pricing: From $0 to $500 a Month
Subscriptions decide the real cost for most individual developers, because the plans bundle model access, usage allowances and the tool itself. The ladder below sorts every verified plan by monthly price so you can see which rung each vendor occupies.
| Monthly price | Product | Plan | What the sources confirm |
|---|---|---|---|
| $0 | Antigravity | Free | Weekly rate limits, unlimited tab completions and command requests, access to multiple agent models |
| $20 | Claude Code | Pro | Claude Code included, per a pricing summary dated Oct. 24 to 28 |
| $20 | Antigravity | Google AI Pro | Entry-level Antigravity quota, per Google’s May 19 plan post |
| $100 | Codex | ChatGPT Pro 100 | Full existing GPT-6 Astra allowance |
| $100 | Claude Code | Max 5x | $100 in monthly Claude Platform API credits |
| $100 | Antigravity | Google AI Ultra (lighter tier) | Introduced May 19 for regular development use |
| $200 | Codex | ChatGPT Pro 200 | Back on sale for new subscribers since late September |
| $200 | Claude Code | Max 20x | $200 in monthly Claude Platform API credits |
| $200 | Antigravity | Google AI Ultra (top tier) | Cut from $250 on May 19 |
| $500 | Codex | ChatGPT Pro 500 | Astra Ultrafast and GPT-6.1 Sol Ultrafast |
A few notes on reading it. The Claude prices come from a secondary pricing summary, not from a directly retrieved Anthropic plan page, so check the earlier $20 to $500 pricing breakdown and Anthropic’s own page before buying. OpenAI reportedly sells ChatGPT Plus at $20 a month with Codex included, though that figure appears in only one source and stays out of the table.
Anthropic’s official pricing page also lists Enterprise at $20 per seat per month on annual billing with a 20-seat minimum, and usage cost scales with the model and the task. Business and Enterprise buyers on the OpenAI side should expect the same pattern, a seat fee plus metered usage, though OpenAI did not publish an Enterprise price in the sources reviewed.
The credit sweeteners
Anthropic added a twist on October 7. Max 5x subscribers receive $100 of monthly Claude Platform credits, Max 20x subscribers $200, and Team subscribers up to $500 pooled across users. These are API credits and not a discount on the Claude Code subscription itself, but they let a Max subscriber run an Opus 5.5 pipeline outside the terminal without a second card on file.
Google went the other way in May. It removed AI credits from the base Google AI plans and repositioned them as an overage mechanism, and it merged Gemini Flash and Gemini Pro usage into a single rate limit calculated by API pricing. In practice that means a heavy Flash user and a heavy Pro user now burn the same quota at rates that track what Google would charge for the tokens.
API Token Pricing and Worked Cost Math
Teams that wire an agent into CI, or developers who pay per token, care about the API rate card. Every price below is per million tokens, standard tier, as listed by the vendors this month.
| Model | Input | Cached input | Output | Used by |
|---|---|---|---|---|
| GPT-6 Astra | $10 | $1 | $50 | Codex |
| GPT-6.1 Sol | $2 | $0.10 | $10 | Codex |
| GPT-6.1 Terra | $1 | $0.05 | $5 | Codex |
| GPT-6 Luna | $0.10 | $0.01 | $0.50 | Codex |
| Claude Opus 5.5 | $4 | $0.20 | $20 | Claude Code, Antigravity |
| Claude Opus 5.5 fast mode | $8 | Not listed | $40 | Claude Code (research preview) |
| Claude Sonnet 5 | $2 | Not listed | $10 | Claude Code |
| Gemini 4 Argon (to Nov. 30) | $2 | 95% off input | $10 | Antigravity |
| Gemini 4 Argon (from Dec. 1) | $4 | 95% off input | $20 | Antigravity |
OpenAI’s enterprise rate card shows a $0.20 cached-input figure for Sol, against $0.10 on its public API page, so confirm the applicable rate in your account documentation.
To make the table concrete, take one coding session that burns 50,000 input tokens and 15,000 output tokens. Anthropic’s cost documentation uses a session of that size as its worked example. The arithmetic below is list price with no caching, so it overstates the bill for any agent that reuses context.
- Claude Opus 5.5: $0.20 for input plus $0.30 for output, $0.50 in total.
- Claude Opus 5.5 fast mode: $0.40 plus $0.60, $1.00 in total.
- GPT-6 Astra: $0.50 plus $0.75, $1.25 in total.
- GPT-6.1 Sol: $0.10 plus $0.15, $0.25 in total.
- GPT-6.1 Terra: $0.05 plus $0.075, about $0.13 in total.
- Gemini 4 Argon before December 1: $0.10 plus $0.15, $0.25 in total.
- Gemini 4 Argon from December 1: $0.20 plus $0.30, $0.50 in total.
Scale that to ten sessions a day over a working month. Opus 5.5 is listed at $4 per million input tokens and $20 per million output tokens. Argon is $2 and $10 during the introductory period, then $4 and $20 after it ends. The cheapest model is not automatically the cheapest outcome, because a model that needs two attempts to produce a mergeable change doubles its own bill. That is exactly why Anthropic frames FrontierCode in terms of cost per merged-quality task rather than cost per token.
Caching changes the picture again. Anthropic’s cost documentation shows a cache read on Opus 5.5 priced at 0.05 times the base input rate, so 40,000 cached input tokens cost $0.008 at the $4 rate. Argon’s cached input is 95% cheaper, which is the same 5% ratio. Astra’s cached input is 10% of its base rate. Long agent loops that keep re-reading the same repository context benefit most from those ratios.
Usage Limits and the Deadlines Before December
Price per token only matters when you can actually use the tokens. Subscription tools govern access through rolling limits, and all three vendors have adjusted those limits recently.
OpenAI’s documentation says Pro 100 and Pro 200 seats, along with Business Premium seats, could use their full existing GPT-6 Astra allowance as of October 29. Plus and Business Standard included limited Astra usage with optional extra credits. The Pro 500 tier consumes included usage at a higher multiple on the Ultrafast models. A tracker at apidog reports that a Codex Pro limit cut takes effect on October 30, and its write-up focuses on what changes for Pro 200 owners. OpenAI had not published matching release-note language in the sources reviewed, so treat the cut as reported.
Anthropic exposes its limits through the product itself. Claude Code’s /usage view breaks down where a session’s tokens went and recommends changes for any behavior behind at least 10% of recent usage. Anthropic’s documentation shows sample recommendations such as switching from max to high effort, compacting before stepping away, and trimming an oversized project instruction file. Prompt cache health appears there too, including the share of input tokens served from cache.
Google’s Antigravity paid plans refresh quota in short windows before a weekly cap, according to one report, and the May plan changes tied that quota to API-priced token consumption. The more disruptive item is a reported change on November 2. Enjoy Agentic Industries says Antigravity will remove Claude models from free accounts, and other reports extend that to some Google AI Plus and trial accounts. Paid Pro and Ultra subscribers keep access to Claude Opus 5.5 and Sonnet 5.5 in the model picker, based on the same community documentation.
Three dates that change the math
- October 30 (reported): Codex Pro usage reduction. Heavy Pro 200 users should log their weekly consumption this week and compare after the change.
- November 2 (reported): Claude models leave some Antigravity free and trial accounts. If your evaluation depends on Opus 5.5 inside Antigravity on a free account, finish it first or move to a paid tier.
- November 30 and December 1 (confirmed by Google): Argon’s introductory $2 and $10 rate ends, and $4 and $20 takes over.
Real-World Examples: Who Is Shipping With Each Agent
Vendor case studies skew positive, so read them as signals of where each product sells, not as proof of quality. Still, they show which agent is landing in which kind of company.
- Oracle uses ChatGPT and Codex. OpenAI published an Oracle case study on October 8 and updated it on October 28. It marks Codex as a tool that large enterprises deploy alongside ChatGPT, not as a developer-only toy.
- ServiceNow puts Codex inside its AI Workflow Factory. OpenAI announced the expanded partnership on October 28. One source says the capability arrives in 2027, so it is announced and not yet generally available.
- PwC rolls out Claude Code and Cowork. A report dated October 27 says PwC planned a joint center of excellence plus training and certification for 30,000 professionals. Treat the headcount as reported, since it comes from one source.
- Barclays expects Claude Code to spread. The bank said on October 1, according to a single report, that it expected Claude Code adoption to reach 50% of its developer population by the end of 2026 and a majority of software engineers in 2027.
- Google’s own teams run Argon in Antigravity. Google says Chrome, Ads and Search teams shipped 35% more code with 30% fewer errors in recent weeks. The company also reports that Argon-assisted work on the open-source Agent Development Kit Python codebase cut long-session in-memory session preparation time by 40% and improved cold-import speed by 21%.
- Anthropic runs Claude Code on its own monorepo. The company said it built an internal version-control system called Scion and moved its monorepo off Git in five months, linking the work to heavier internal Claude Code use.
- Scientists get a free Antigravity tier. On October 13, Google said it would offer the highest Antigravity usage tier free for six months to 10,000 scientists, subject to eligibility and capacity. Two days later it described Antigravity as an agentic science workbench for antimicrobial-peptide research.
The pattern is useful. Codex sells through enterprise software partnerships and ChatGPT seats. Claude Code spreads through consultancies, banks and its own maker’s engineering teams. Antigravity pushes through Google Cloud, its own product teams and a science-credit program.
For developers also weighing an editor-first alternative, a three-way review of Antigravity against Cursor and Claude Code covers the free-versus-$200 split from the IDE side.
Parallel Agents, Safety Modes and Control
Raw model quality is one axis. How the tool lets you supervise several agents at once, and how it stops a bad command, is the other.
Codex now has the most explicit multi-agent story. OpenAI’s macOS app, released October 28, is described as a command center for running multiple coding agents in parallel. Codex also entered preview in the ChatGPT mobile app on May 14, so a developer can stay connected to work running on a Mac host. A composer-prediction beta, which suggests the next message in a thread, began rolling out on October 9. And OpenAI says an Astra-enabled Codex can ask clarifying questions mid-task and keep working on independent steps while it waits for the answer.
Claude Code takes a terminal-first route with a desktop app layered on top. Reports say the desktop app can run several local and remote sessions in parallel. Anthropic’s alignment team published research on October 22 about attacks on the production safety classifiers of two tools, Claude Code’s Auto Mode and Codex’s Guardian. According to a summary of that report, Auto Mode has been Claude Code’s production default since September. Anthropic also notes that Skills, the reusable agent-knowledge format it developed while building Claude Code, have been adopted by Codex, Cursor and OpenCode. It donated Agent Skills to the Agentic AI Foundation as an open standard on October 22.
Antigravity bets on breadth over parallel orchestration. It spans an app, a CLI and IDE extensions, a model picker that includes rival vendors, and a sibling product in Google Cloud’s Gemini agent, which Google describes as a universal work agent for planning tasks, using tools and connecting to business systems. Google also tied Antigravity into the Gemini macOS app on launch day for Argon.
If you compare these tools with other CLI agents, the Codex, Cursor and Claude Code spending-cap comparison shows how the same safety and limit trade-offs play out when an editor wraps the model.
Use-Case Recommendations
The right answer shifts with the job. These seven scenarios map the data above to a pick, and each states what would change the recommendation.
- Solo developer on a tight budget. Start with Antigravity Free at $0, then step to Google AI Pro at $20 for the entry quota. Watch the reported November 2 Claude removal if you want Opus 5.5 on a free account, and plan for Argon’s December 1 API rate if you call it directly.
- Hardest refactors and migrations. Claude Code with Opus 5.5 carries the strongest published merge-readiness result (54.6% FrontierCode), and Anthropic markets the model for long-running agentic coding. Budget for Max 5x at $100 if you run it all day.
- Company already on ChatGPT Business or Enterprise. Use Codex. The seat controls, the Oracle and ServiceNow deployments and the Google Cloud distribution plan all point to enterprise as its home turf.
- Speed-sensitive interactive work. Compare Astra Ultrafast (up to 300 tokens per second, Pro 500 and Enterprise) with Opus 5.5 fast mode (up to 2.5 times faster at $8 and $40). Both cost a premium, so confirm the latency win matters before you pay it.
- Google Cloud shop. Antigravity through Gemini Enterprise fits, and Google lists Claude Opus 5.5 and Sonnet 5.5 as available to eligible Google Cloud customers, which lets a team test two vendors in one console.
- High-volume routine edits. Route to cheaper tiers. GPT-6.1 Terra at $1 and $5, Claude Haiku 5.5 as a subagent, or Gemini 3.8 Flash at medium effort all cut spend. Reserve the flagship for the small share of tickets that need it.
- Scientists and researchers. Take the six-month free top Antigravity tier if you qualify, and check Anthropic’s AI-for-Science program, which reportedly offers free Claude access to 10,000 scientists as of October 27.
Teams that also evaluate GitHub’s assistant can start from a comparison of Claude Code, Codex and Copilot by developer share. Anyone who prefers open-source terminals should look at the OpenCode, Codex CLI and Gemini CLI star-count comparison, since Google is steering Gemini Code Assist customers toward Antigravity and away from the older products.
Migration Guide: Moving Between Codex, Claude Code and Antigravity
Switching agents costs less than switching editors, because all three work against the same Git repository. What you actually migrate is habits, instruction files and spend controls. The steps below assume a working team of two to ten developers.
- Inventory your agent instructions. List the project instruction files, such as a CLAUDE.md that Anthropic’s cost docs mention, and any reusable Skills. Anthropic says Codex, Cursor and OpenCode have adopted Skills, so those travel better than prompt text pasted into a chat.
- Pick a pilot set of ten real tickets. Mix bug fixes, a refactor, a test-writing job and one ambiguous feature request. Vendor charts cannot tell you how a tool handles your codebase.
- Pin the model per tool. In Antigravity, administrators enable Claude Opus 5.5 and Sonnet 5.5 first, then developers choose them in the model picker or with the /model command, according to a report on Google Cloud’s October 20 announcement. In Codex, make sure the CLI is current, since one source says Astra needs build 0.153.0 or newer.
- Run each ticket through two tools. Record whether the change merged without edits, how many review rounds it took and how long the agent ran. Count merged changes, not tokens.
- Capture cost per merged change. Divide the subscription share or API spend by the number of changes that merged. A pricier model that merges on the first attempt often beats a cheap one that needs two.
- Set spend and context guards. Use Claude Code’s /usage recommendations, compact long sessions before you leave them idle, and start new sessions with /clear so totals reset. In Codex, route routine edits to Sol or Terra and keep Astra for the hard cases.
- Plan for the dated changes. Put October 30, November 2 and December 1 on the team calendar and re-run the cost table on each date.
- Decide per workload, not per company. Many teams will end up running two tools. Antigravity’s own model picker already blends Gemini and Claude, which shows vendors expect mixed fleets.
A starter command set for the Claude Code side of a pilot looks like this.
# Inspect where tokens went in the current session
/usage
# Drop from max to high effort when a task does not need max
/effort high
# Compact long context before stepping away
/compact
# Start fresh and reset the session cost totals
/clearOn the Antigravity side, enterprise rollout runs through Gemini Enterprise, and Google’s Antigravity Gemini Enterprise announcement explains how agentic workflows reach every developer under a company plan. For a view of how it stacks against other editor-based rivals, see the comparison of Antigravity, Kiro and Windsurf.
Common migration mistakes
- Comparing flagship against flagship on price alone. Opus 5.5 at $4 and $20 looks twice as expensive as Argon at $2 and $10, until December 1 equalizes them.
- Ignoring retired models. OpenAI removed GPT-5.5 from Codex on October 14, so any saved workflow pinned to it fails or silently falls back.
- Treating reported limits as final. The October 30 and November 2 changes come from third-party trackers. Verify them against the vendor release notes.
- Skipping a shadow week. Running a new agent on production tickets without a baseline hides regressions.
Pros and Cons of Each Agent
OpenAI Codex
Pros
- Widest model ladder from Astra down to Luna, with API prices from $0.10 to $10 per million input tokens.
- Parallel-agent macOS app, mobile preview and an Ultrafast tier rated at up to 300 tokens per second.
- Deep enterprise footprint through ChatGPT seats, the Oracle case study, ServiceNow and Google Cloud.
Cons
- Top-tier access lives on $100, $200 and $500 plans, and a Codex Pro limit cut is reported for October 30.
- Locked to OpenAI models inside the tool, and OpenAI removed GPT-5.5 on October 14, which shows how fast model names change.
- Astra costs $10 and $50 per million tokens, five times Sol’s rate.
Claude Code
Pros
- Strongest published merge-readiness figure of the three (54.6% FrontierCode, vendor-run) at a lower per-token price than Astra.
- Clear subscription ladder at $20, $100 and $200, plus API credits on Max and Team plans.
- Opus 5.5 is offered on AWS, Google Cloud and Microsoft Azure, and Skills, the format Anthropic developed for Claude Code, has been adopted by other tools.
Cons
- Claude models only, and no free plan in the sources reviewed.
- Opus 5.5 fast mode doubles the per-token price to $8 and $40 per million tokens in Claude Code.
- The $20 to $200 pricing summary comes from a secondary source, so confirm it on Anthropic’s page.
Google Antigravity
Pros
- The only tool of the three that starts at $0 and offers Gemini, Claude and open-weight models in one picker.
- Google reports sizable internal gains with Argon, including more than 35% more agentic code submissions.
- Distribution through the app, CLI, IDE extensions and Google Cloud.
Cons
- Argon’s price doubles on December 1, and a reported November 2 change removes Claude from some free accounts.
- Plan quotas were rewritten in May, with credits repositioned as overage, which makes monthly spend harder to predict.
- Google’s strongest claims are internal, and Carbon, announced October 28, is not yet confirmed in the product.
Final Verdict: Which Coding Agent Wins on the Data
No tool wins every column, but the data supports a clear ranking for each buyer type.
For output quality per dollar on hard tasks, Claude Code with Opus 5.5 leads on the only head-to-head number available. Anthropic’s FrontierCode result of 54.6% against Astra’s 53.3% comes at about a fifth of the cost per task, and Opus 5.5’s $4 and $20 list price sits well below Astra’s $10 and $50. The caveat is that Anthropic ran the test, so an independent replication would move this from strong signal to settled fact.
For enterprise rollout and parallel work, Codex has the broadest footprint. It owns the macOS multi-agent app, the mobile preview, the Ultrafast tier and the ChatGPT seat structure. It also costs the most at the top end, with Pro 500 at $500 and Astra at $50 per million output tokens.
For the lowest barrier to entry, Antigravity wins on price alone ($0 Free, $20 Pro). Its weakness is volatility. A reported Claude removal on November 2 and an Argon price step on December 1 mean a free-tier evaluation done today may not hold next month.
Here is the scorecard in plain terms.
| Buyer priority | Best pick | Why |
|---|---|---|
| Merge quality on hard tickets | Claude Code | 54.6% FrontierCode, $4 / $20 per million tokens |
| Enterprise seats and parallel agents | Codex | macOS app, mobile preview, Business and Enterprise plans |
| Lowest entry price | Antigravity | $0 Free plan, $20 Google AI Pro |
| Fastest output | Codex (Ultrafast) | Up to 300 tokens per second, Pro 500 and Enterprise |
| Mixed-vendor model choice | Antigravity | Gemini, Claude and GPT-OSS in one model picker |
| Cheapest routine model | Codex (Terra) | $1 / $5 per million tokens |
My recommendation for a typical five-person team: put Claude Code on the two engineers who handle migrations and incident fixes, give everyone Antigravity Free or Pro for exploration, and keep Codex in play only if the company already pays for ChatGPT Business. Revisit the split on December 1, when Argon’s new rate and the November limit changes are all in effect. For more on the surrounding model market, the AI and machine learning hub tracks each vendor’s next release, including the latest AI model coverage.
Frequently Asked Questions
Is Codex better than Claude Code?
It depends on the job. Anthropic’s FrontierCode result favors Opus 5.5 over GPT-6 Astra by 54.6% to 53.3%, but Anthropic ran that test. Codex leads on parallel-agent tooling, the macOS app and enterprise plans.
Is Claude Code free?
The sources reviewed do not confirm a free Claude Code plan. A pricing summary dated October 24 to 28 lists Claude Code as included with Pro at $20 a month, Max 5x at $100 and Max 20x at $200.
Is Google Antigravity free?
Google lists a Free plan at $0 a month with weekly rate limits, unlimited tab completions and unlimited command requests. Paid tiers start with Google AI Pro at $20 a month.
Which model does each tool use?
Codex runs OpenAI’s GPT-6 family, led by Astra with Sol, Terra and Luna below it. Claude Code runs Claude Opus 5.5, Sonnet 5.5 and Haiku 5.5. Antigravity lists Gemini 4 Argon and Gemini 3.8 Flash alongside Claude Opus 5.5 and Sonnet 5.5 Thinking and GPT-OSS 120B.
What happens to Gemini 4 Argon pricing after November 30?
Google’s introductory $2 per million input tokens and $10 per million output tokens ends on November 30, 2026. From December 1, the standard price is $4 and $20, which matches Claude Opus 5.5’s list price.
Does Codex still support GPT-5.5?
No. OpenAI removed GPT-5.5 from ChatGPT, ChatGPT Work and Codex on October 14, 2026. The API was not affected.
Is Gemini 4 Carbon available in Antigravity?
Google announced Gemini 4 Carbon on October 28 and says it builds on Argon, but the sources reviewed do not confirm general availability in Antigravity. Argon is the current confirmed Antigravity flagship.
Should I use more than one coding agent?
Many teams will. A split such as Claude Code for hard migrations, Antigravity for exploration and a cheaper Codex tier for routine edits spreads cost and risk. Track cost per merged change across tools for at least two weeks before you consolidate.
