The best Claude model for most coding work is Sonnet 5.5. It offers the most sensible starting balance of capability, speed and price. When a bug has unpacked its suitcase and started paying rent in your repository, try Opus 5.5.
Start with Sonnet 5.5
Anthropic lists Sonnet 5.5 at $2 per million input tokens and $10 per million output tokens through its API. In CursorBench 4.0, Sonnet 5.5 Max scored 55.5% on ambiguous, multi-file coding tasks.
That does not make it the champion of every language and codebase. It does make Sonnet a reasonable first choice for everyday features, bug fixes and code reviews—before you release the more expensive dragons.
Infographic: Claude model roles, API rates and selected CursorBench 4.0 Max results. Benchmark results are specific to Cursor’s agent and test suite.
Use Opus when the problem fights back
Opus 5.5 costs $4 per million input tokens and $20 per million output tokens. Its Max configuration led the inspected CursorBench table with 57.8%, but cost $13.43 per task. Opus High scored 56.0% at $3.97.
Those are Cursor’s reported task costs, not your Claude subscription bill. Still, the comparison makes one point rather loudly: turning every setting to “maximum” can be an expensive way to feel powerful.
Where Haiku and Fable fit
Haiku 5.5 is the budget candidate for fast, repetitive work. Its API rates start at $0.10 input and $0.50 output per million tokens, although longer prompts cost more.
Fable 5.1 is a specialist escalation option at $10 input and $50 output per million tokens. It scored below Opus Max in this Cursor test, proving that a larger bill does not automatically arrive wearing a superhero cape.
Run a tiny code audition
- Fix a contained bug with a known failing test.
- Build one feature that touches several files.
- Review code containing a defect you already know about.
- Record successful runs, regressions, retries and review time.
Use equivalent prompts and permissions. Your own repository is a better judge than a leaderboard wearing a nice tie.
The verdict
Start with Sonnet 5.5. Move to Opus 5.5 when the task is ambiguous or repeated failures are costing more than the upgrade. Use Haiku for suitable high-volume work, and consider Fable only after your own tests show a reason.
Before paying, check the current Claude plans and confirm that your coding tool offers the model and effort setting you want.
This article was created with the help of Sylar AI, our in-house AI assistant.