Claude Opus 5.5 — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Developer | Anthropic |
|---|---|
| Type | Reasoning / agentic |
| Modality | Text, vision |
| Parameters | Undisclosed |
| License | Proprietary |
| Open weights | No |
| Released | 2026-09 |
| Input price | $4.00 /1M |
| Output price | $20.00 /1M |
| API providers | Anthropic API, AWS, Google Cloud, Microsoft Azure |
Benchmarks
| Anthropic-reported | Terminal-Bench 4.0 66.4%; FrontierCode v1.1 54.4%; CursorBench 4.0 57.8%; GDPval-AA v2.1 1846 Elo; OSWorld 2.0 81.8% (partial) |
|---|
What is Claude Opus 5.5?
Claude Opus 5.5 is Anthropic’s flagship everyday model, released on 22 September 2026 as the first model of the Claude 5.5 family. According to Anthropic, it performs at the level of Claude Fable 5.1 on most work and generates output more than 30% faster than Opus 5.
It is also cheaper than Opus 5: $4 per million input tokens and $20 per million output (Opus 5: $5 / $25), with cache reads at $0.20 and cache writes at $5 per million. An optional Fast mode is billed at $8 / $40. Anthropic raised the five-hour usage limits on its Pro, Max, Team and seat-based Enterprise plans alongside the launch, and says Claude Sonnet 5.5 and Haiku 5.5 follow in the coming weeks.
What it means for everyday Claude and ChatGPT users is covered in Claude Opus 5.5 and GPT-6 Sol: what changes for you.
Claude Opus 5.5 pricing: API cost per 1M tokens
| Input (per 1M tokens) | $4.00 |
|---|---|
| Output (per 1M tokens) | $20.00 |
| Output/input ratio | 5× |
| Blended (4:1 in:out) | $7.20 per 1M tokens |
What Claude Opus 5.5 costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Workload | Tokens / month | Cost / month |
|---|---|---|
| Side project | 1M in / 0.25M out | $9.00 |
| Small team | 20M in / 5M out | $180 |
| Production | 200M in / 50M out | $1,800 |
Run your own numbers in the AI API cost calculator.
Cheaper alternatives to Claude Opus 5.5
| Model | Blended $/1M | You save |
|---|---|---|
| Mistral 7B open | $0.0220 | 100% cheaper |
| Llama 3.1 8B open | $0.0220 | 100% cheaper |
| Mistral NeMo 12B open | $0.0240 | 100% cheaper |
Frequently asked questions
How much does Claude Opus 5.5 cost per 1M tokens?
Claude Opus 5.5 costs $4.00 per 1M input tokens and $20.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $7.20 per 1M tokens.
How much does Claude Opus 5.5 cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $180 on Claude Opus 5.5. A side project (1M in / 0.25M out) costs roughly $9.00.
What is a cheaper alternative to Claude Opus 5.5?
Mistral 7B is the strongest cheaper option in our database at $0.0220 per 1M blended — about 100% less than Claude Opus 5.5. It is also open-weight, so self-hosting is an option.
Can I run Claude Opus 5.5 locally?
No. Claude Opus 5.5 is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does Claude Opus 5.5 charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. Claude Opus 5.5 charges 5× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
See every Claude model priced side by side: Claude API pricing.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the AI models database or the LLM leaderboard.