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Claude Opus 5.5 vs Gemini 3.7 Flash

Updated October 21, 2026. 91 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace Claude Opus 5.5 Replace Gemini 3.7 Flash
Claude Opus 5.5Anthropic
Coding
92.2
Overall
57.6
Output $/M
$20.00
86
Gemini 3.7 FlashGoogle
Coding
69.9
Overall
39.6
Output $/M
$3.75
5
vs boards won of 91 shared

Decision reading

Pick Claude Opus 5.5 for coding: it scores 92.2 on the Vibe Coding Index against 69.9 for Gemini 3.7 Flash.

Pick Gemini 3.7 Flash when output tokens cost 5.3x less, or when the context window is larger, 1.05M against 1M tokens.

Model AClaude Opus 5.5Anthropic92.2/1002 independent benchmarksNo cost per solved taskModel BGemini 3.7 FlashGoogle69.9/1002 independent benchmarks$1.78 per solved task
Shared results
91
Claude Opus 5.5 only
16
Gemini 3.7 Flash only
21
Like-for-like categories
8 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
Claude Opus 5.5 92.2 from 2 benchmarks, Gemini 3.7 Flash 69.9 from 2 benchmarks.
Widest category
Math, 21.0 points apart on average over 6 shared benchmarks.
Widest single gap
FrontierMath, tier 4: Claude Opus 5.5 95.0% against Gemini 3.7 Flash 36.6%, 58.4 points apart on a 0 to 100 scale.
Output price
Claude Opus 5.5 $20.00 against Gemini 3.7 Flash $3.75 per million output tokens, 5.3x apart.
Context window
Claude Opus 5.5 takes 1M tokens, Gemini 3.7 Flash 1.05M.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryClaude Opus 5.5BarsGemini 3.7 FlashTies
Coding180
Intelligence20
Agentic work131
Reasoning111
Math60
Knowledge51
Web design80
General232
All shared boards865
CodingLike-for-likeFour of these boards feed the Vibe Coding Index180
Coding benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
LiveBench coding96.3%80.5%Claude Opus 5.5
LMArena WebDev18071591Claude Opus 5.5
AA Coding IndexNot measured71.5Only Gemini 3.7 Flash measured
LiveCodeBench (Vals AI)Not measured88.7%Only Gemini 3.7 Flash measured
SWE-bench Verified (Vals AI)Not measured80.8%Only Gemini 3.7 Flash measured
Terminal-Bench 4 (Vals AI)65.2%12.1%Claude Opus 5.5
Vibe Code Bench (Vals AI)90.3%70.4%Claude Opus 5.5
Code migration (Vals AI)66.7%34.8%Claude Opus 5.5
ProgramBench (Vals AI)18.5%0.0%Claude Opus 5.5
IOI (Vals AI)95.1%67.8%Claude Opus 5.5
Terminal-Bench 2.1 (Vals AI)87.6%77.5%Claude Opus 5.5
SWE-bench Multimodal (Vals AI)70.2%Not measuredOnly Claude Opus 5.5 measured
Vibe Code Bench 1-100 (Vals AI)30.4%Not measuredOnly Claude Opus 5.5 measured
SkillsBench (Vals AI)Not measured65.9%Only Gemini 3.7 Flash measured
CyberBench (Vals AI)74.6%43.8%Claude Opus 5.5
SciCode66.9%59.8%Claude Opus 5.5
FrontierCode54.6%43.6%Claude Opus 5.5
FrontierSWE62.3%20.3%Claude Opus 5.5
MirrorCode77.4%Not measuredOnly Claude Opus 5.5 measured
ALE-Bench2147.4904.3Claude Opus 5.5
LMArena Text: coding15451499Claude Opus 5.5
LMArena Text: software and IT15381498Claude Opus 5.5
LMArena WebDev: React18551587Claude Opus 5.5
LMArena WebDev: HTML17531593Claude Opus 5.5
LMArena WebDev: from an image17531599Claude Opus 5.5
Neither model has a result on the other 13 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
AA Intelligence Index57.639.6Claude Opus 5.5
Epoch Capabilities Index168.8158.0Claude Opus 5.5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index131
Agentic work benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
Design Arena: agents building web apps13161224Claude Opus 5.5
Design Arena: agents building full-stack appsNot measured1208Only Gemini 3.7 Flash measured
Design Arena: agents building mobile apps13111230Claude Opus 5.5
Design Arena: agents building Android appsNot measured1247Only Gemini 3.7 Flash measured
Design Arena: agents building Godot gamesNot measured1264Only Gemini 3.7 Flash measured
Design Arena: agents building gamesNot measured1235Only Gemini 3.7 Flash measured
Design Arena: spreadsheets13591028Claude Opus 5.5
LiveBench research85.0%76.5%Claude Opus 5.5
LiveBench browser80.0%56.0%Claude Opus 5.5
LiveBench long agentic85.0%28.3%Claude Opus 5.5
SREBench (Vals AI)33.6%4.6%Claude Opus 5.5
Finance Agent (Vals AI)58.6%59.0%Gemini 3.7 Flash
Tax Agent Bench (Vals AI)45.6%22.8%Claude Opus 5.5
Legal Research Bench (Vals AI)50.5%34.6%Claude Opus 5.5
Harvey's Legal Agent Benchmark (Vals AI)9.2%Not measuredOnly Claude Opus 5.5 measured
Excel Modeling Benchmark (Vals AI)75.9%71.3%Claude Opus 5.5
BioMysteryBench (Vals AI)79.3%Not measuredOnly Claude Opus 5.5 measured
Terminal-Bench-Science (Vals AI)47.1%7.1%Claude Opus 5.5
Vals Science Index58.7%Not measuredOnly Claude Opus 5.5 measured
Time Horizon Index (Vals AI)91.3%Not measuredOnly Claude Opus 5.5 measured
CUA-bench (Vals AI)14.0%Not measuredOnly Claude Opus 5.5 measured
Robo-bench (Vals AI)14.6%Not measuredOnly Claude Opus 5.5 measured
APEX-Agents73.5%67.8%Claude Opus 5.5
Remote Labor Index21.3%5.0%Claude Opus 5.5
SpireClimb3.3%Not measuredOnly Claude Opus 5.5 measured
Vending-Bench 2$9,235Not measuredOnly Claude Opus 5.5 measured
LMArena Search1213Not measuredOnly Claude Opus 5.5 measured
Neither model has a result on the other 12 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index111
Reasoning benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
GPQA DiamondNot measured93.9%Only Gemini 3.7 Flash measured
LiveBench reasoning92.2%87.8%Claude Opus 5.5
MysteryMechanism (Vals AI)49.5%Not measuredOnly Claude Opus 5.5 measured
MMMU Pro (Vals AI)Not measured89.0%Only Gemini 3.7 Flash measured
GPQA Diamond (Artificial Analysis run)Not measured94.5%Only Gemini 3.7 Flash measured
Humanity's Last Exam (Artificial Analysis run)61.4%47.9%Claude Opus 5.5
GPQA Diamond (Epoch AI run)90.6%94.8%Gemini 3.7 Flash
ARC-AGI98.5%95.5%Claude Opus 5.5
ARC-AGI-293.3%84.6%Claude Opus 5.5
Chess puzzles67.0%66.0%Claude Opus 5.5
Mystery game puzzles71.0%37.0%Claude Opus 5.5
EBR-bench71.4%Not measuredOnly Claude Opus 5.5 measured
LMArena Text: hard prompts15361495Claude Opus 5.5
LMArena Text: expert15491512Claude Opus 5.5
LMArena Text: hard prompts in English15351487Claude Opus 5.5
LMArena Vision: diagrams13451329Claude Opus 5.5
LMArena Vision: homework13621320Claude Opus 5.5
Neither model has a result on the other 4 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index60
Math benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
OTIS Mock AIME100.0%97.2%Claude Opus 5.5
FrontierMath, tiers 1 to 391.2%71.6%Claude Opus 5.5
FrontierMath, tier 495.0%36.6%Claude Opus 5.5
ProofBench100.0%58.0%Claude Opus 5.5
LMArena Text: math15181511Claude Opus 5.5
LMArena Text: mathematical work15161502Claude Opus 5.5
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index51
Knowledge benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
MMLU ProNot measured90.1%Only Gemini 3.7 Flash measured
LegalBench (Vals AI)Not measured87.3%Only Gemini 3.7 Flash measured
TaxEval (Vals AI)Not measured74.7%Only Gemini 3.7 Flash measured
MortgageTax (Vals AI)Not measured66.7%Only Gemini 3.7 Flash measured
MedCode (Vals AI)49.8%53.4%Gemini 3.7 Flash
SimpleQA Verified72.2%69.2%Claude Opus 5.5
LMArena Text: science15241511Claude Opus 5.5
LMArena Text: medicine and healthcare15091494Claude Opus 5.5
LMArena Text: legal and government15181496Claude Opus 5.5
LMArena Text: business and finance14941479Claude Opus 5.5
Neither model has a result on the other 7 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index80
Web design benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
Design Arena: websites13351304Claude Opus 5.5
Design Arena: UI components13901299Claude Opus 5.5
Design Arena: game dev14571318Claude Opus 5.5
Design Arena: data viz13971315Claude Opus 5.5
Design Arena: 3D14771308Claude Opus 5.5
Design Arena: all code categories13901308Claude Opus 5.5
Design Arena: SVG13321283Claude Opus 5.5
Design Arena: ASCII artNot measured1276Only Gemini 3.7 Flash measured
LiveBench design86.9%73.2%Claude Opus 5.5
GeneralLike-for-likePublic boards, shown as published, kept out of the index232
General benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
Vals Index70.2%Not measuredOnly Claude Opus 5.5 measured
LiveBench data analysis80.3%68.0%Claude Opus 5.5
Public Benefits Bench (Vals AI)70.6%Not measuredOnly Claude Opus 5.5 measured
SAGE (Vals AI)45.8%49.2%Gemini 3.7 Flash
MedScribe (Vals AI)91.4%83.9%Claude Opus 5.5
Long context reasoning (AA-LCR)84.7%83.0%Claude Opus 5.5
DTBench98.9%96.8%Claude Opus 5.5
LMCA68.2%50.4%Claude Opus 5.5
Furniture assembly83.3%26.7%Claude Opus 5.5
LMArena Text15161489Claude Opus 5.5
LMArena Text: instruction following15371484Claude Opus 5.5
LMArena Text: creative writing15351488Claude Opus 5.5
LMArena Vision13211314Claude Opus 5.5
LMArena Text: English15191483Claude Opus 5.5
LMArena Text: non-English15071487Claude Opus 5.5
LMArena Text: Chinese15821552Claude Opus 5.5
LMArena Text: GermanNot measured1506Only Gemini 3.7 Flash measured
LMArena Text: Japanese15341511Claude Opus 5.5
LMArena Text: KoreanNot measured1481Only Gemini 3.7 Flash measured
LMArena Text: French14931500Gemini 3.7 Flash
LMArena Text: Spanish15081495Claude Opus 5.5
LMArena Text: Russian15171515Claude Opus 5.5
LMArena Text: PolishNot measured1503Only Gemini 3.7 Flash measured
LMArena Text: multi-turn15011485Claude Opus 5.5
LMArena Text: longer queries15321492Claude Opus 5.5
LMArena Text: writing and language15321491Claude Opus 5.5
LMArena Text: entertainment and media15151477Claude Opus 5.5
LMArena Vision: English13171309Claude Opus 5.5
LMArena Vision: ChineseNot measured1394Only Gemini 3.7 Flash measured
LMArena Vision: reading text13261322Claude Opus 5.5
LMArena Vision: humorNot measured1299Only Gemini 3.7 Flash measured
LMArena Vision: creative writing13201312Claude Opus 5.5
Neither model has a result on the other 14 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Opus 5.5 and Gemini 3.7 Flash
BenchmarkClaude Opus 5.5Gemini 3.7 FlashLeader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Claude Opus 5.5$0.014Fits in one request
Gemini 3.7 Flash$0.0026Fits in one request

Gemini 3.7 Flash costs less

Repository review

50K input + 3K output tokens

Claude Opus 5.5$0.260Fits in one request
Gemini 3.7 Flash$0.049Fits in one request

Gemini 3.7 Flash costs less

Agent loop

200K input + 10K output tokens

Claude Opus 5.5$1.00Fits in one request
Gemini 3.7 Flash$0.188Fits in one request

Gemini 3.7 Flash costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Claude Opus 5.5 and Gemini 3.7 Flash
SpecificationAnthropic Claude Opus 5.5Google Gemini 3.7 Flash
MakerAnthropicGoogle
WeightsNo public weights listedNo public weights listed
ReleasedSeptember 22, 2026August 13, 2026
Context window1M1.05M
Input $/Mtok$4.00$0.75
Output $/Mtok$20.00$3.75
Coding index92.269.9
Independent measurements behind it22
Cost per solved taskNot computable$1.78
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Opus 5.5 better than Gemini 3.7 Flash for coding?

Pick Claude Opus 5.5 for coding: it scores 92.2 on the Vibe Coding Index against 69.9 for Gemini 3.7 Flash. Pick Gemini 3.7 Flash when output tokens cost 5.3x less, or when the context window is larger, 1.05M against 1M tokens.

Which is cheaper, Claude Opus 5.5 or Gemini 3.7 Flash?

Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Gemini 3.7 Flash costs $0.75 and $3.75. Cost per solved task is known for Gemini 3.7 Flash only.

Which has the bigger context window, Claude Opus 5.5 or Gemini 3.7 Flash?

Gemini 3.7 Flash, with 1.05M tokens against 1M.

How many benchmarks is the Claude Opus 5.5 vs Gemini 3.7 Flash comparison based on?

91 benchmarks have a result for both models as of October 21, 2026. Claude Opus 5.5's coding index rests on 2 independent benchmarks and Gemini 3.7 Flash's on 2. Where only one model has a result, the page says so instead of naming a winner.

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