Claude Opus 5.5
Top public pick for coding, agents and hard questions at a mid price; skip it for bulk work where Sonnet 5.5 is enough.
This product is made by Anthropic, whose Claude models help draft our reviews. How we keep that from tilting a score
Going away: Claude Opus 5.5 fast mode on Azure / Microsoft Foundry, on 15 Jan 2027. Source: learn.microsoft.com, read 19 Oct 2026.
Should you use it?
Pick it if
People who want the top-ranked model for coding, agents and writing, and can pay $20 a month or API prices.
Best for: Coding and agent jobs; ranks first on the web app and agent boards (Chat models Top 20)
Skip it if
You run high volumes of simple tasks; Sonnet 5.5 is close on most boards at half the token price, as is OpenAI's GPT-6.1 Sol.
You give up: Twice Sonnet 5.5's token price; thinking can't be turned off
The short version
- What this is
- Anthropic's main large model, released 22 Sep 2026, used in the Claude apps, Claude Code and the API.
- Why it matters
- It leads or nearly leads the public boards for coding, agents and writing, so most people get frontier quality without paying Fable prices.
- First on arena.ai WebDev and Agent, second on Creative Writing, first on the Artificial Analysis index s1 s3 s5 s7.
- Needs Pro at $20/month in the app; the API costs $4 / $20 per 1M tokens s9 s10.
- Anthropic itself says to start here before trying Fable 5.1 s14.
Good at
Our take
Opus 5.5 is the model to start with if you can pay $20 a month. On 11 Oct 2026 it leads the arena.ai WebDev and Agent boards s1 s3 and the Artificial Analysis index s5, and it ranks second on Creative Writing s7. Its research score, 97, is below its coding and writing scores because it ranks 6th on the Expert board, which still has a wide rank spread s6, so treat that one as less settled than coding and agents.
The catch is cost at the top setting. At max effort it costs about $6 per index task s5, so the high setting, which leads the Agent board at $1.61 a task s4, is the sensible default. For lots of simple work, Sonnet 5.5 is close behind for half the token price.
Scores by job
A score from 0 to 100 per job, against everything available today. Overall 98 across 3 jobs, the average of the job scores.
New to this? What the scores and labels mean
- 0 to 100
- Our score for one job, like writing or coding, compared with everything else out today. 100 is the best available today. For AI models we build it from public data, such as Arena's blind votes and Epoch AI's independent tests; apps and tools are scored on our own checklist. The same tool can score differently for different jobs, and where two likely ranges overlap, we call it a tie.
- Our verdict
- Use it: a top choice for most people. Worth trying: good, and worth a go. Depends: good for some people or one kind of job. Wait: too early to tell, or not out for everyone yet. Skip: something else does the job better.
- First look
- Just released. We say what it is and whether to bother, and give it a score once public results exist.
- No score yet
- None of the public sources we use covers it yet, or the only evidence is from a source whose numbers we can't use, so we describe it in words instead.
- Best buy
- Nothing cheaper scores as well for that job.
- Best free
- The best score for that job that costs nothing, through a free plan or by running on your own computer.
- Pay as you go
- No monthly plan: you pay for each use, usually through a developer account.
- Checked
- The day we last confirmed the score and the price against the sources. Prices change often, so check the date.
- AI model
- The engine underneath, like GPT or Claude. You use it through an app or, if you code, directly.
- Open source
- Free to download and run on your own computer, so nothing leaves your machine.
The top score of the 21 we have scored for this job.
From blind votes (Arena) and independent tests (Epoch AI) · Arena data, CC BY 4.0, Epoch AI data, CC BY 4.0
1 source so farData read 20 Oct
The top score of the 12 we have scored for this job.
From blind votes (Arena) · Arena data, CC BY 4.0
1 source so farData read 20 Oct
#2 of the 15 we have scored for this job.
From blind votes (Arena) and independent tests (Epoch AI) · Arena data, CC BY 4.0, Epoch AI data, CC BY 4.0
2 sourcesData read 20 Oct
#1 in Arena's blind votes for agents. Those votes give a rank but no rating, so there is no score yet.
#1 in Arena's blind votes for agents (rank only, no score yet) · Arena data, CC BY 4.0
2 sourcesData read 20 Oct
Alternatives
Better or cheaper for agents, from our scores, then the ones we'd also look at. The same kind of product comes first.
- Gemini 4 ArgonCheaperText model#6$4.99 a monthRanked #6 on Arena's Agent board in agents for $4.99 a month, against $20 a month here. Side by side
- MiMo-V2.6-ProFreeText model#13FreeRanked #13 on Arena's Agent board in agents, with a free plan. Side by side
- Claude Sonnet 5.5Text model#5$20 a monthNear the top on WebDev and Expert at half the token price, and on the Free plan. Side by side
- Claude Fable 5.1Text model#3$100 a monthAnthropic's pick only when Opus 5.5 at high effort still falls short; it costs 2.5x more per token. Side by side
Value for money
Where it sits in agents: higher is a better score, further left is cheaper. Green dots are the Best buys.
Evidence
Everything behind the call and the scores, folded so the page stays short. Spotted a wrong price, score or link? Report a mistake.
How we scored this
The coding, writing and research scores are our own, built from public data: blind votes on Arena and, where they cover the job, Epoch AI's independent tests. How we combine them is our method and we don't publish it. For agents, Arena's blind votes give a rank but no rating, so we show the rank and no score yet.
Public leaderboardIndependent test
This product is made by Anthropic, whose Claude models help draft our reviews.
Reviews are drafted with help from AI models, including Anthropic's Claude. Model scores come only from outside leaderboards and independent evaluations, by a written rule.
No one paid for this review or gave us free access, and we earn nothing if you sign up. How we score
Sources 14
- s1arena.ai Code Arena: WebDev leaderboard
- s2arena.ai Text: Coding leaderboard
- s3arena.ai Agent leaderboard
- s4arena.ai Agent Pareto and cost per task
- s5Artificial Analysis LLM leaderboard
- s6arena.ai Text: Expert leaderboard
- s7arena.ai Text: Creative Writing leaderboard
- s8arena.ai Text: Instruction Following leaderboard
- s9Claude plans and pricing
- s10Claude API pricing
- s11Claude privacy: is my data used for model training (consumer)
- s12Claude privacy: is my data used for model training (commercial)
- s13Anthropic: Introducing Claude Opus 5.5
- s14Claude models overview
Something here out of date or wrong? Report a mistake and we will check it against the source.
History 2 changes
Every change to a rating, the price or our call, with the reason. Scores are against what exists on the day, so they drift down as better things ship. Older entries come from before we moved to scores.
- New: Coding ratedNew: Agents ratedNew: Research ratedNew: Writing ratedReviewed: coding, agents, research, writing.
- Audit: Agent cost per task relabelled (the $1.61 figure is the Pareto view's 14-day median; the main table's median is $1.76). Softened the 'every public board' claim. Ratings unchanged.
Use it well 4 guides on this site
Pages on this site that help with the jobs above.