Claude Opus 4.5 vs Gemini 3.5 Flash
Wins 1 of 8 areas
Long documents
Wins 7 of 8 areas
Coding · Agents · Reasoning · Facts · Images and charts · Math · Following instructions
Gemini 3.5 Flash is the stronger all-rounder.Claude Opus 4.5 is better at long documents.
Scores updated · 41 tests both models report · How we compare
Where each one wins
Tests won in each of the eight areas we test. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking05Gemini 3.5 Flash5 of 5 tests
- CodingWriting and fixing software24Gemini 3.5 Flash4 of 6 tests
- MathCompetition and research-level math13Gemini 3.5 Flash3 of 5 tests · 1 tie
- Images and chartsUnderstanding pictures, charts and video02Gemini 3.5 Flash2 of 2 tests
- Following instructionsDoing exactly what it is asked02Gemini 3.5 Flash2 of 2 tests
- AgentsCarrying out multi-step tasks on its own12Gemini 3.5 Flash2 of 3 tests
- FactsGetting facts right instead of making them up12Gemini 3.5 Flash2 of 3 tests
- Long documentsFinding answers in very long texts10Claude Opus 4.51 of 1 test
Long documents rests on a single test.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Gemini 3.5 Flash costs 65% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Gemini 3.5 Flash pulls ahead
- Abstract visual puzzles that people can solveARC-AGI-2+34.5points ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+28.4points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+21.9points ahead
Where Claude Opus 4.5 pulls ahead
- Real work tasks from 44 professionsGDPVal+12.1points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+6.1points ahead
- Reasons across sets of long documentsAA-LCR+4points ahead
Every test, side by side
All 41 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGemini 3.5 Flash
- LiveBench · Agentic CodingGemini 3.5 Flash by 9.339.749+9.3
- Terminal-Bench HardClaude Opus 4.5 by 6.14740.9+6.1
- SciCodeGemini 3.5 Flash by 4.449.553.9+4.4
- SWE-bench ProGemini 3.5 Flash by 3.15255.1+3.1
- LMArena · WebDevGemini 3.5 Flash by 30 rating points14691499+30 rating
- LiveBench · CodingClaude Opus 4.5 by 1.579.778.2+1.5
AgentsGemini 3.5 Flash
- MCP AtlasGemini 3.5 Flash by 21.362.383.6+21.3
- GDPValClaude Opus 4.5 by 12.147.335.2+12.1
- OSWorld-VerifiedGemini 3.5 Flash by 12.166.378.4+12.1
ReasoningGemini 3.5 Flash
- ARC-AGI-2Gemini 3.5 Flash by 34.537.672.1+34.5
- Humanity's Last ExamGemini 3.5 Flash by 12.630.142.7+12.6
- CritPtGemini 3.5 Flash by 8.54.613.1+8.5
- GPQA DiamondGemini 3.5 Flash by 5.686.692.2+5.6
- LiveBench · ReasoningGemini 3.5 Flash by 1.980.182+1.9
FactsGemini 3.5 Flash
- SimpleQA VerifiedGemini 3.5 Flash by 20.545.766.2+20.5
- AA-Omniscience · AccuracyGemini 3.5 Flash by 4.846.651.4+4.8
- AA-Omniscience · Non-hallucinationClaude Opus 4.5 by 1.23937.8+1.2
Images and chartsGemini 3.5 Flash
- CharXiv (RQ)Gemini 3.5 Flash by 1767.284.2+17
- MMMU-ProGemini 3.5 Flash by 10.37484.3+10.3
MathGemini 3.5 Flash
- FrontierMath Tiers 1-3 (v2)Gemini 3.5 Flash by 28.434.462.8+28.4
- FrontierMath Tier 4Gemini 3.5 Flash by 21.94.926.8+21.9
- HMMT Feb. 2026Gemini 3.5 Flash by 10.285.395.5+10.2
- LiveBench · MathematicsClaude Opus 4.5 by 2.290.488.2+2.2
- AIME 2026tie95.195tie
Following instructionsGemini 3.5 Flash
- IFBenchGemini 3.5 Flash by 18.35876.3+18.3
- LiveBench · Instruction FollowingGemini 3.5 Flash by 1362.575.6+13
Other results14 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- AA Agentic IndexClaude Opus 4.5 by 32.359.627.3+32.3
- Artificial Analysis Coding IndexGemini 3.5 Flash by 22.347.870.1+22.3
- Terminal-Bench 2.0Gemini 3.5 Flash by 16.959.376.2+16.9
- ToolathlonGemini 3.5 Flash by 1343.556.5+13
- ARC-AGI-1Gemini 3.5 Flash by 10.58292.5+10.5
- frontiermath_tier_4_v1Gemini 3.5 Flash by 10.44.214.6+10.4
- MotionBenchGemini 3.5 Flash by 10.360.370.6+10.3
- livebench_data_analysisClaude Opus 4.5 by 9.574.464.9+9.5
- AA-OmniscienceGemini 3.5 Flash by 7.21421.2+7.2
- τ²-Bench Telecom (AA run)Gemini 3.5 Flash by 5.889.595.3+5.8
- AA IntelligenceGemini 3.5 Flash by 3.529.132.6+3.5
- livebench_languageGemini 3.5 Flash by 3.381.384.6+3.3
- Finance AgentGemini 3.5 Flash by 2.755.257.9+2.7
- LiveBenchClaude Opus 4.5 by 17675+1
Questions people ask
Which is better, Claude Opus 4.5 or Gemini 3.5 Flash?
Gemini 3.5 Flash wins seven of the eight areas we test: coding, agents, reasoning, facts, images and charts, math and following instructions. Claude Opus 4.5 wins long documents.
Which is better for coding?
Gemini 3.5 Flash. It wins 4 of the 6 coding tests both models report; Claude Opus 4.5 wins 2.
Which is cheaper?
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. That makes Gemini 3.5 Flash about 65% cheaper for the same work.
How do you compare the two?
We use the 41 benchmark tests both models have published scores on. The verdict counts the 27 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 14 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.