Enter opens the highlighted result. Esc closes.

Claude Opus 4.5 vs Gemini 3.5 Flash

Claude Opus 4.5 leads Gemini 3.5 Flash on coding, 44.0 to 39.8 on the Vibe Coding Index, and Gemini 3.5 Flash costs 2.8x less per output token ($9.00 vs $25.00 per million). Updated October 21, 2026; 82 benchmarks have a result for both.

Replace Claude Opus 4.5 Replace Gemini 3.5 Flash
Claude Opus 4.5Anthropic
Coding
44.0
Overall
55.7
Output $/M
$25.00
15
Gemini 3.5 FlashGoogle
Coding
39.8
Overall
63.8
Output $/M
$9.00
67
vs boards won of 82 shared

Claude Opus 4.5 or Gemini 3.5 Flash: which to pick

Pick Claude Opus 4.5 for coding: it scores 44.0 on the Vibe Coding Index against 39.8 for Gemini 3.5 Flash, though on 3 benchmarks against 4.

Pick Gemini 3.5 Flash for output tokens 2.8x cheaper ($9.00 vs $25.00 per million) and a lower cost per solved task ($1.21 against $1.37).

Model AClaude Opus 4.5Anthropic44.0/1003 independent benchmarks$1.37 per solved taskModel BGemini 3.5 FlashGoogle39.8/1004 independent benchmarks$1.21 per solved task
Shared results
82
Claude Opus 4.5 only
26
Gemini 3.5 Flash only
30
Like-for-like categories
8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

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 4.5 44.0 from 3 benchmarks, Gemini 3.5 Flash 39.8 from 4 benchmarks.
Widest category
Math, 12.7 points apart on average over 6 shared benchmarks.
Widest single gap
ARC-AGI-2: Claude Opus 4.5 37.6% against Gemini 3.5 Flash 72.1%, 34.4 points apart on a 0 to 100 scale.
Output price
Claude Opus 4.5 $25.00 against Gemini 3.5 Flash $9.00 per million output tokens, 2.8x apart.
Context window
Claude Opus 4.5 takes 200K tokens, Gemini 3.5 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 4.5BarsGemini 3.5 FlashTies
Coding37
Intelligence02
Agentic work15
Reasoning113
Math15
Knowledge48
Web design17
General420
All shared boards1567
CodingLike-for-likeSix of these boards feed the Vibe Coding Index37
Coding benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
SWE-bench Verified79.2%Not measuredOnly Claude Opus 4.5 measured
SWE-bench (full test set)52.6%Not measuredOnly Claude Opus 4.5 measured
SWE-bench Multilingual70.7%Not measuredOnly Claude Opus 4.5 measured
LMArena WebDev14941499Gemini 3.5 Flash
LiveCodeBench (Vals AI)83.7%87.6%Gemini 3.5 Flash
SWE-bench Verified (Vals AI)76.4%78.8%Gemini 3.5 Flash
Terminal-Bench 4 (Vals AI)Not measured6.1%Only Gemini 3.5 Flash measured
Vibe Code Bench (Vals AI)20.6%48.7%Gemini 3.5 Flash
Code migration (Vals AI)Not measured26.8%Only Gemini 3.5 Flash measured
ProgramBench (Vals AI)Not measured0.0%Only Gemini 3.5 Flash measured
Terminal-Bench 2.1 (Vals AI)Not measured74.2%Only Gemini 3.5 Flash measured
SkillsBench (Vals AI)Not measured52.7%Only Gemini 3.5 Flash measured
LiveCodeBench (Artificial Analysis run)87.1%Not measuredOnly Claude Opus 4.5 measured
SciCodeNot measured53.9%Only Gemini 3.5 Flash measured
Terminal-Bench Hard (Artificial Analysis run)47.0%46.2%Claude Opus 4.5
Terminal-Bench63.1%Not measuredOnly Claude Opus 4.5 measured
GSO-Bench26.5%Not measuredOnly Claude Opus 4.5 measured
WeirdML63.7%62.6%Claude Opus 4.5
Cybench82.0%Not measuredOnly Claude Opus 4.5 measured
ALE-BenchNot measured911.0Only Gemini 3.5 Flash measured
LMArena Text: coding15031493Claude Opus 4.5
LMArena Text: software and IT14831494Gemini 3.5 Flash
LMArena WebDev: React14781495Gemini 3.5 Flash
LMArena WebDev: HTML15101522Gemini 3.5 Flash
LMArena WebDev: from an imageNot measured1504Only Gemini 3.5 Flash measured
SciCodeNot measured12.3%Only Gemini 3.5 Flash measured
Neither model has a result on the other 13 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
Intelligence benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
AA Intelligence Index29.133.6Gemini 3.5 Flash
Epoch Capabilities Index150.1154.9Gemini 3.5 Flash
Agentic workLike-for-likePublic boards, shown as published, kept out of the index15
Agentic work benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
Design Arena: agents building web apps11591202Gemini 3.5 Flash
Design Arena: agents building full-stack apps11561197Gemini 3.5 Flash
Design Arena: agents building mobile apps11891174Claude Opus 4.5
Design Arena: agents building Android apps11751184Gemini 3.5 Flash
Design Arena: agents building Godot gamesNot measured1098Only Gemini 3.5 Flash measured
Design Arena: agents building gamesNot measured1180Only Gemini 3.5 Flash measured
Design Arena: HTML slidesNot measured1142Only Gemini 3.5 Flash measured
Design Arena: PowerPoint slidesNot measured1179Only Gemini 3.5 Flash measured
Finance Agent (Vals AI)Not measured57.9%Only Gemini 3.5 Flash measured
Tax Agent Bench (Vals AI)Not measured21.6%Only Gemini 3.5 Flash measured
Legal Research Bench (Vals AI)Not measured30.8%Only Gemini 3.5 Flash measured
Excel Modeling Benchmark (Vals AI)Not measured63.5%Only Gemini 3.5 Flash measured
Terminal-Bench-Science (Vals AI)Not measured5.7%Only Gemini 3.5 Flash measured
τ²-Bench Telecom89.5%95.6%Gemini 3.5 Flash
APEX-AgentsNot measured27.5%Only Gemini 3.5 Flash measured
METR time horizons75.0%Not measuredOnly Claude Opus 4.5 measured
Remote Labor Index3.8%Not measuredOnly Claude Opus 4.5 measured
GDPval45.5%Not measuredOnly Claude Opus 4.5 measured
BALROG43.5%Not measuredOnly Claude Opus 4.5 measured
DeepResearch Bench54.8%Not measuredOnly Claude Opus 4.5 measured
OSWorld66.3%Not measuredOnly Claude Opus 4.5 measured
Vending-Bench 2$4,967$5,396Gemini 3.5 Flash
Berkeley Function Calling Leaderboard (BFCL)77.5%Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 18 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index113
Reasoning benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
GPQA Diamond85.9%92.7%Gemini 3.5 Flash
MMMU Pro (Vals AI)83.0%88.3%Gemini 3.5 Flash
GPQA Diamond (Artificial Analysis run)86.6%92.2%Gemini 3.5 Flash
Humanity's Last Exam (Artificial Analysis run)30.1%42.7%Gemini 3.5 Flash
GPQA Diamond (Epoch AI run)86.0%92.8%Gemini 3.5 Flash
ARC-AGI80.0%92.5%Gemini 3.5 Flash
ARC-AGI-237.6%72.1%Gemini 3.5 Flash
SimpleBench62.0%76.7%Gemini 3.5 Flash
Chess puzzles14.0%45.0%Gemini 3.5 Flash
Mystery game puzzles22.0%32.0%Gemini 3.5 Flash
EBR-bench14.3%4.8%Claude Opus 4.5
VPCT40.0%Not measuredOnly Claude Opus 4.5 measured
LMArena Text: hard prompts14761488Gemini 3.5 Flash
LMArena Text: expert14871495Gemini 3.5 Flash
LMArena Text: hard prompts in English14821483Gemini 3.5 Flash
LMArena Vision: diagramsNot measured1323Only Gemini 3.5 Flash measured
LMArena Vision: homeworkNot measured1330Only Gemini 3.5 Flash measured
Kagi LLM Benchmark80.2%Not measuredOnly Claude Opus 4.5 measured
Neither model has a result on the other 4 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index15
Math benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
AIME95.4%Not measuredOnly Claude Opus 4.5 measured
MGSM (Vals AI)95.2%Not measuredOnly Claude Opus 4.5 measured
AA Math Index91.3Not measuredOnly Claude Opus 4.5 measured
AIME 2025 (Artificial Analysis run)91.3%Not measuredOnly Claude Opus 4.5 measured
OTIS Mock AIME86.1%95.6%Gemini 3.5 Flash
FrontierMath, tiers 1 to 334.4%62.8%Gemini 3.5 Flash
FrontierMath, tier 44.9%26.8%Gemini 3.5 Flash
ProofBench36.0%31.0%Claude Opus 4.5
LMArena Text: math14631504Gemini 3.5 Flash
LMArena Text: mathematical work14681495Gemini 3.5 Flash
Neither model has a result on the other 3 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index48
Knowledge benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
MMLU Pro87.3%89.5%Gemini 3.5 Flash
LegalBench (Vals AI)84.6%83.6%Claude Opus 4.5
CaseLaw (Vals AI)62.6%Not measuredOnly Claude Opus 4.5 measured
CorpFin (Vals AI)65.1%64.7%Claude Opus 4.5
TaxEval (Vals AI)74.9%74.4%Claude Opus 4.5
MortgageTax (Vals AI)68.7%68.1%Claude Opus 4.5
MedQA (Vals AI)95.9%Not measuredOnly Claude Opus 4.5 measured
MedCode (Vals AI)49.2%55.8%Gemini 3.5 Flash
MMLU Pro (Artificial Analysis run)89.5%Not measuredOnly Claude Opus 4.5 measured
SimpleQA Verified45.7%66.2%Gemini 3.5 Flash
GeoBench75.0%Not measuredOnly Claude Opus 4.5 measured
LMArena Text: science14541495Gemini 3.5 Flash
LMArena Text: medicine and healthcare14441483Gemini 3.5 Flash
LMArena Text: legal and government14591488Gemini 3.5 Flash
LMArena Text: business and finance14481467Gemini 3.5 Flash
FACTS Benchmark Suite43.9%63.1%Gemini 3.5 Flash
Neither model has a result on the other 2 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index17
Web design benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
Design Arena: websites12471268Gemini 3.5 Flash
Design Arena: UI components12381273Gemini 3.5 Flash
Design Arena: game dev12291263Gemini 3.5 Flash
Design Arena: data viz12431236Claude Opus 4.5
Design Arena: 3D12141244Gemini 3.5 Flash
Design Arena: all code categories12421266Gemini 3.5 Flash
Design Arena: SVG11811254Gemini 3.5 Flash
Design Arena: ASCII art11901254Gemini 3.5 Flash
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index420
General benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 FlashLeader
Public Benefits Bench (Vals AI)Not measured59.5%Only Gemini 3.5 Flash measured
SAGE (Vals AI)52.1%49.9%Claude Opus 4.5
MedScribe (Vals AI)85.3%76.6%Claude Opus 4.5
Vals Multimodal IndexNot measured62.9%Only Gemini 3.5 Flash measured
IFBench58.0%76.3%Gemini 3.5 Flash
Long context reasoning (AA-LCR)77.3%74.3%Claude Opus 4.5
DTBench89.9%94.7%Gemini 3.5 Flash
LMCA44.5%47.1%Gemini 3.5 Flash
CL-bench21.1%Not measuredOnly Claude Opus 4.5 measured
Surface Evolver BenchNot measured58.1%Only Gemini 3.5 Flash measured
Furniture assembly28.3%Not measuredOnly Claude Opus 4.5 measured
LMArena Text14511482Gemini 3.5 Flash
LMArena Text: instruction following14781467Claude Opus 4.5
LMArena Text: creative writing14451470Gemini 3.5 Flash
LMArena VisionNot measured1308Only Gemini 3.5 Flash measured
LMArena Text: English14611481Gemini 3.5 Flash
LMArena Text: non-English14381475Gemini 3.5 Flash
LMArena Text: Chinese14701527Gemini 3.5 Flash
LMArena Text: German14491494Gemini 3.5 Flash
LMArena Text: Japanese14171486Gemini 3.5 Flash
LMArena Text: Korean14241448Gemini 3.5 Flash
LMArena Text: French14711490Gemini 3.5 Flash
LMArena Text: Spanish14571480Gemini 3.5 Flash
LMArena Text: Russian14471493Gemini 3.5 Flash
LMArena Text: Polish14391516Gemini 3.5 Flash
LMArena Text: multi-turn14661481Gemini 3.5 Flash
LMArena Text: longer queries14791483Gemini 3.5 Flash
LMArena Text: writing and language14521478Gemini 3.5 Flash
LMArena Text: entertainment and media14341459Gemini 3.5 Flash
LMArena Vision: EnglishNot measured1305Only Gemini 3.5 Flash measured
LMArena Vision: ChineseNot measured1377Only Gemini 3.5 Flash measured
LMArena Vision: reading textNot measured1317Only Gemini 3.5 Flash measured
LMArena Vision: humorNot measured1321Only Gemini 3.5 Flash measured
LMArena Vision: creative writingNot measured1301Only Gemini 3.5 Flash measured
LMArena Document14621463Gemini 3.5 Flash
Neither model has a result on the other 11 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Opus 4.5 and Gemini 3.5 Flash
BenchmarkClaude Opus 4.5Gemini 3.5 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 4.5$0.018Fits in one request
Gemini 3.5 Flash$0.0060Fits in one request

Gemini 3.5 Flash costs less

Repository review

50K input + 3K output tokens

Claude Opus 4.5$0.325Fits in one request
Gemini 3.5 Flash$0.102Fits in one request

Gemini 3.5 Flash costs less

Agent loop

200K input + 10K output tokens

Claude Opus 4.5$1.25Exceeds the context window
Gemini 3.5 Flash$0.390Fits in one request

Gemini 3.5 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 4.5 and Gemini 3.5 Flash
SpecificationAnthropic Claude Opus 4.5Google Gemini 3.5 Flash
MakerAnthropicGoogle
WeightsNo public weights listedNo public weights listed
ReleasedNovember 24, 2025May 19, 2026
Context window200K1.05M
Input $/Mtok$5.00$1.50
Output $/Mtok$25.00$9.00
Coding index44.039.8
Independent measurements behind it34
Cost per solved task$1.37$1.21
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Opus 4.5 better than Gemini 3.5 Flash for coding?

Pick Claude Opus 4.5 for coding: it scores 44.0 on the Vibe Coding Index against 39.8 for Gemini 3.5 Flash, though on 3 benchmarks against 4. Pick Gemini 3.5 Flash for output tokens 2.8x cheaper ($9.00 vs $25.00 per million) and a lower cost per solved task ($1.21 against $1.37).

Which is cheaper, Claude Opus 4.5 or Gemini 3.5 Flash?

Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Gemini 3.5 Flash costs $1.50 and $9.00. Per solved SWE-bench Verified task, Claude Opus 4.5 costs $1.37 and Gemini 3.5 Flash $1.21.

Which has the bigger context window, Claude Opus 4.5 or Gemini 3.5 Flash?

Gemini 3.5 Flash, with 1.05M tokens against 200K.

How many benchmarks is the Claude Opus 4.5 vs Gemini 3.5 Flash comparison based on?

82 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 3 independent benchmarks and Gemini 3.5 Flash's on 4. Where only one model has a result, the page says so instead of naming a winner.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/claude-opus-4-5-vs-gemini-3-5-flash" title="Claude Opus 4.5 vs Gemini 3.5 Flash, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/claude-opus-4-5-vs-gemini-3-5-flash">LLMBenchmark.ai, Claude Opus 4.5 vs Gemini 3.5 Flash</a></p>