Claude Opus 5.5 vs gpt-oss-120b

Price, context window & benchmark comparison

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Claude Opus 5.5

Anthropic
$4.00 / $20.00
Input / Output · per 1M tokens
VS
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gpt-oss-120b

OpenAI
$0.15 / $0.60
Input / Output · per 1M tokens
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Verdict: gpt-oss-120b is 30.5× cheaper than Claude Opus 5.5 on a typical 3:1 input/output mix. Claude Opus 5.5 scores higher on the Artificial Analysis Intelligence Index (57.6 vs 11.6). Claude Opus 5.5 has the larger context window (1M vs 131K).
Claude Opus 5.5gpt-oss-120b
Input price / 1M$4.00$0.15
Output price / 1M$20.00$0.60
Blended price (3:1)$8.00$0.26
Cached input / 1M$0.20$0.075
Context window1M131K
Max output128K66K
Intelligence index57.611.6
Coding index30.4
Providers11
Best provider uptime (30m)100.0%
Vision inputYesNo
ReasoningYesYes
Tool callingYesYes
Released2026-09-222025-08-05
Retirement

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FAQ

Which is cheaper, Claude Opus 5.5 or gpt-oss-120b?

gpt-oss-120b is 30.5× cheaper than Claude Opus 5.5 on a typical 3:1 input/output mix.

Claude Opus 5.5 vs gpt-oss-120b: which has a bigger context window?

Claude Opus 5.5: 1,000,000 tokens. gpt-oss-120b: 131,072 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: Claude Opus 5.5 ≈ $18,000, gpt-oss-120b ≈ $600.00.

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