Noometry

Model comparison

Claude Opus 5.5 vs GPT-6.1 Sol

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 65.6 on the Noometry Index. GPT-6.1 Sol costs 2.0× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 32 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

GPT-6.1 Sol OpenAI

65.6

Rank #6 Confirmed

Summary

  • They share 32 benchmarks with published results for both. Claude Opus 5.5 scores higher in 7 categories and GPT-6.1 Sol in 3 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Claude Opus 5.5 leads 78.2 to 63.6.
  • The biggest single-benchmark swing is EBR-Bench: 71.4% for Claude Opus 5.5 and 54.3% for GPT-6.1 Sol.
  • GPT-6.1 Sol is cheaper at $2 / $10 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • GPT-6.1 Sol accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 5.5GPT-6.1 Sol
ProviderAnthropicOpenAI
Noometry Index68.665.6
Released2026-09-222026-09-29
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$4$2
Output $ / M tokens$20$10
Results tracked4434

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), GPT-6.1 Sol: 63.2 (#8)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
FrontierCode54.6%50.2%
LMArena WebDev18131755
SciCode66.9%55.8%
LMArena Coding15471487
DeepSWE—75.2%
CursorBench57.8%—
FrontierSWE62.3%—
MirrorCode77.4%—
ALE-Bench2,147—

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#15), GPT-6.1 Sol: 39.6 (#26)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
APEX-Agents73.5%60%
GDP.pdf30.6%32%
Vending-Bench 29,235—

Reasoning GPT-6.1 Sol leads

Claude Opus 5.5: 80.2 (#3), GPT-6.1 Sol: 81.9 (#2)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
ARC-AGI-293.3%94.2%
NYT Connections (extended)88.5%95.5%
ARC-AGI-198.5%98.5%
CritPt31.7%31.7%
EBR-Bench71.4%54.3%
LMArena Hard Prompts15351466
Mystery Game Puzzles71%80%
Epoch Capabilities Index167.33166.09
Chess Puzzles—61%
DTBench98.9%—
LMCA68.2%—

Math GPT-6.1 Sol leads

Claude Opus 5.5: 91.8 (#3), GPT-6.1 Sol: 93.7 (#1)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
FrontierMath (Tiers 1-3)91.2%93.7%
FrontierMath Tier 495%100%
OTIS Mock AIME 2024-2025100%100%
ProofBench100%99%
LMArena Math15061464
FrontierMath Erdős2.9%—

Knowledge GPT-6.1 Sol leads

Claude Opus 5.5: 66.4 (#10), GPT-6.1 Sol: 71.8 (#4)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
GPQA Diamond90.6%95.4%
SimpleQA Verified72.2%73.9%
LMArena Expert15471502

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 57.8 (#1), GPT-6.1 Sol: 52.7 (#5)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
LMArena Vision13211288
Furniture Assembly83.3%80%
Blueprint-Bench 251.2%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), GPT-6.1 Sol: 54.3 (#46)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
LMArena Non-English15071438
LMArena Chinese15881477
LMArena Russian15201455
LMArena French1514—
LMArena Spanish1507—

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), GPT-6.1 Sol: 77.0 (#29)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
LMArena Instruction Following15371468

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.1 (#19), GPT-6.1 Sol: 44.9 (#54)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
LMArena Longer Query15321465

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), GPT-6.1 Sol: 63.6 (#63)

BenchmarkClaude Opus 5.5GPT-6.1 Sol
LMArena Text15151447
LMArena Creative Writing15331432
LMArena Multi-Turn14991449
EQ-Bench Creative Writing2050—

Frequently asked questions

Is Claude Opus 5.5 better than GPT-6.1 Sol?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 65.6 on the Noometry Index. GPT-6.1 Sol costs 2.0× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or GPT-6.1 Sol?

GPT-6.1 Sol is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or GPT-6.1 Sol better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 63.2 in the Noometry coding category.

Which has the bigger context window?

GPT-6.1 Sol does, with 1.05M tokens against 1M.

How many benchmarks do Claude Opus 5.5 and GPT-6.1 Sol share?

32 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and GPT-6.1 Sol has 34.

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