MODEL PROOF
Claude Opus 5.5
FRONTIER
Nothing is both better and cheaper under this workload.
- Independent LMArena score
- 1,511.7 ± 9.05 · 4,552 votes
- Context window
- 1M
- Maximum output
- 128K
- Input modalities
- text, image, file
- Output modalities
- text
- Published input price
- $4.00 / 1M tokens
- Published output price
- $20.00 / 1M tokens
- Pricing kind
- fixed
Inspect complete billing conditions and endpoint terms below.
Price from Anthropic: the cheapest offer that is serving, at standard delivery and at the maker’s precision or better, at its standard rate.
Every price dimension · USD per million tokens
| Input | $4.00/M |
|---|---|
| Output | $20.00/M |
| Cached input | $0.200/M |
| Cache write | $5.00/M |
| Cache write 1h | $8.00/M |
| Reasoning | Unknown/M |
| Web search | $0.01/call |
Who sells it
The same weights, different shops. Cheapest is not like-for-like when serving precision differs.
11 provider offers · rates, limits and conditions
Rates are USD per million tokens. Endpoint terms can differ even when the quoted price and precision match. A listed parameter is a provider declaration, not a task-success test.
| Seller | Input | Output | Precision | Uptime (1d) |
|---|---|---|---|---|
| Amazon Bedrockamazon-bedrock Endpoint terms
| $4.00 | $20.00 | undeclared | 93.87% |
| Azureazure/global Endpoint terms
| $4.00 | $20.00 | undeclared | 99.99% |
| Googlegoogle-vertex/global Endpoint terms
| $4.00 | $20.00 | undeclared | 99.95% |
| Claude Platform on AWSclaude-on-aws Endpoint terms
| $4.00 | $20.00 | undeclared | 99.88% |
| Anthropicanthropic Endpoint terms
| $4.00 | $20.00 | undeclared | 99.94% |
| Amazon Bedrockamazon-bedrock/eu-west-1 Endpoint terms
| $4.40 | $22.00 | undeclared | 99.91% |
| Amazon Bedrockamazon-bedrock/us-east-1 Endpoint terms
| $4.40 | $22.00 | undeclared | 99.44% |
| Azureazure/us Endpoint terms
| $4.40 | $22.00 | undeclared | — |
| Googlegoogle-vertex/us Endpoint terms
| $4.40 | $22.00 | undeclared | 100.00% |
| Googlegoogle-vertex/europe Endpoint terms
| $4.40 | $22.00 | undeclared | 99.99% |
| Anthropicanthropic/fast Endpoint terms
| $8.00 | $40.00 | undeclared | 100.00% |
Independent scores
| LMArena Elo | 1511.7high |
|---|
LMArena Elo under CC BY 4.0. Absence of another board is not a score of zero.
Best rankings by task
- Code categories #1 1414
- Game development #1 1480
- Data visualisation #1 1408
- 3D #1 1492
- SVG #1 1335
- UI components #2 1402
- Mobile apps #2 1328
- Websites #3 1342
Per-task Elo and rank from Design Arena, via OpenRouter’s model feed. The rank is the feed’s, and it counts models OpenRouter does not list.
Capability
| Context window | 1M |
|---|---|
| Max output | 128K |
| Input modes | text, image, file |
| Tool use | yes |
| Reasoning | always on |
| Open weights | no |
Provenance
| Price source | openrouter.ai |
|---|---|
| Fetched | 2026-10-06 |
| Quality data | verified |
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code...
Questions this page answers
What does Claude Opus 5.5 cost?
$4.00/M in, $20.00/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription.
Does Claude Opus 5.5 have an independent quality score?
Claude Opus 5.5 has an LMArena score in this catalogue.
What beats Claude Opus 5.5?
Nothing is both better and cheaper than Claude Opus 5.5.
Does this page use Artificial Analysis scores for Claude Opus 5.5?
No. Artificial Analysis figures are not published here. Quality on this page is LMArena Elo where a score exists; otherwise the row is unrated.
MODEL MONUMENT
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The verdict as one SVG, for a README or a docs page. It states this model's dominance status at the balanced workload on the LMArena lens, with the date it was computed, and it is rebuilt with the catalogue — so it changes when the verdict changes, including to one you would rather it did not.
[](https://undominated.ai/models/anthropic__claude-opus-5.5/)<a href="https://undominated.ai/models/anthropic__claude-opus-5.5/"><img src="https://undominated.ai/badge/anthropic__claude-opus-5.5.svg" alt="Claude Opus 5.5 — Undominated.ai dominance verdict" height="36"></a>Direct file: https://undominated.ai/badge/anthropic__claude-opus-5.5.svg — a static SVG, written by scripts/build-badges.mjs on every build, so the copy you embed is never
older than the last deploy.
