MODEL PROOF
Claude Opus 5.5
BETTER VALUE OPTION
A stored alternative has an equal-or-higher measured score and an equal-or-lower price.
Gemini 4 Argon · Δ score 17.7 points · same measured price · $8.00 / 1M tokens (Price under confirmation since Oct 21, 2026)
- Independent LMArena score
- 1,515.5 ± 7.52 · 7,687 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, with at least 90% of the reference context 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 | 99.79% |
| Azureazure/global Endpoint terms
| $4.00 | $20.00 | undeclared | 100.00% |
| Googlegoogle-vertex/global Endpoint terms
| $4.00 | $20.00 | undeclared | 100.00% |
| Claude Platform on AWSclaude-on-aws Endpoint terms
| $4.00 | $20.00 | undeclared | 100.00% |
| Anthropicanthropic Endpoint terms
| $4.00 | $20.00 | undeclared | 100.00% |
| Amazon Bedrockamazon-bedrock/eu-west-1 Endpoint terms
| $4.40 | $22.00 | undeclared | 100.00% |
| Amazon Bedrockamazon-bedrock/us-east-1 Endpoint terms
| $4.40 | $22.00 | undeclared | 100.00% |
| 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 | 100.00% |
| Anthropicanthropic/fast Endpoint terms
| $8.00 | $40.00 | undeclared | 100.00% |
Independent scores
| LMArena Elo | 1515.5high |
|---|---|
| LMArena row | claude-opus-5.5-high |
LMArena Elo under CC BY 4.0. Absence of another board is not a score of zero.
Best rankings by task
- Code categories #1 1390
- UI components #1 1394
- Data visualisation #1 1397
- 3D #1 1477
- SVG #1 1333
- Game development #2 1457
- Mobile apps #2 1312
- Web apps #2 1317
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 | 2026-10-21 |
| 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?
Gemini 4 Argon has an equal-or-higher measured score and an equal-or-lower price.
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.
