Claude Opus 5 vs GPT-5.5
Side-by-side comparison of API pricing, specs, benchmarks, and capabilities
| Specification |
by Anthropic
|
by OpenAI
|
|---|---|---|
| Overview | ||
| Status | Current flagship | Current flagship |
| Released | ||
| Pricing per million tokens | ||
| Input | $5.00/Mtok | $5.00/Mtok |
| Output | $25.00/Mtok | $30.00/Mtok |
| Blended avg | $10.00/Mtok | $11.25/Mtok |
| Cached input | $0.500/Mtok | $0.500/Mtok |
| Specifications | ||
| Context window | 1M tokens | 1M tokens |
| Parameters | Proprietary | Proprietary |
| Speed (TPS) | — | — |
| Modalities | ||
| Input |
textimage
|
textimageaudio
|
| Benchmarks source: Vellum LLM Leaderboard | ||
| Avg benchmark score | 84.2 | 75 |
| Perf / dollar | 8.4 | 6.7 |
| BrowseComp | 90.8 | 84.4 |
| Humanity's Last Exam | 64.7 | 41.4 |
| AutoBench | 26 | 12.9 |
| GPQA Diamond | — | 93.6 |
| SWE-Bench Verified | 97 | — |
| Terminal-Bench 2.1 | — | 82.7 |
| MCP Atlas | — | 75.3 |
| OSWorld-Verified | — | 78.7 |
| ARC-AGI 2 | — | 85 |
| HumanEval | — | 58.6 |
| Independent composite scores each on its own scale — not part of the average above | ||
| AA Intelligence Index | 50.7 | 38.6 |
| AA Agentic Index | 56.2 | 37.3 |
| AA-Omniscience Index (−100–100) | 37.1 | 20.5 |
| GDPval-AA v2 | 1735.1 ELO | 1491.1 ELO |
| LMSYS Chatbot Arena | — | 1476.1 ELO |
| Providers | ||
| Available from |
Anthropic — $5.00/$25.00/Mtok
|
OpenAI — $5.00/$30.00/Mtok
|
Cost at scale
1M tokens · 50/50 input/output| Volume | Claude Opus 5 | GPT-5.5 | Savings |
|---|---|---|---|
| 1M tokens | $10 | $11.25 | $1.25 (11.1%) |
| 10M tokens | $100 | $112.5 | $12.5 (11.1%) |
| 100M tokens | $1000 | $1125 | $125 (11.1%) |
| 1000M tokens | $10000 | $11250 | $1250 (11.1%) |
When to pick which
distilled from the pricing and spec data above- cost dominates: $10.00/Mtok blended vs $11.25 — 11.1% less on the same 50/50 token mix
- raw capability matters more than price: 84.2 vs 75 average benchmark score
- this pairing gives GPT-5.5 no edge on price, context, cache discount, or measured performance — pick it only for qualitative fit (ecosystem, compliance, model behavior on your prompts)
The cheaper option here — Claude Opus 5 costs $10.00/Mtok blended on Anthropic.
Summary
Claude Opus 5 by Anthropic costs $5.00/Mtok input and $25.00/Mtok output, with a 1M-token context window. It supports text, image input.
GPT-5.5 by OpenAI costs $5.00/Mtok input and $30.00/Mtok output, with a 1M-token context window. It supports text, image, audio input.
On a blended cost basis, Claude Opus 5 is 11.1% cheaper than GPT-5.5.
On benchmarks, Claude Opus 5 scores higher (84.2 vs 75) on average. In terms of value, Claude Opus 5 has better performance per dollar (8.4 vs 6.7).
Note: Pricing is per million tokens. Actual costs vary with usage patterns, prompt caching, and batch discounts. Always verify against official provider pricing pages.