Claude Sonnet 4 vs Gemini 2.5 Flash Lite
Wins 7 of 7 areas
Coding · Agents · Reasoning · Facts · Images and charts · Long documents · Following instructions
Wins 0 of 7 areas
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Claude Sonnet 4 is the stronger all-rounder.Gemini 2.5 Flash Lite is cheaper.
Scores updated · 32 tests both models report · How we compare
Where each one wins
Tests won in each of the seven areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software30Claude Sonnet 43 of 3 tests
- ReasoningHard problems that need careful thinking20Claude Sonnet 42 of 3 tests · 1 tie
- Images and chartsUnderstanding pictures, charts and video20Claude Sonnet 42 of 2 tests
- FactsGetting facts right instead of making them up21Claude Sonnet 42 of 3 tests
- AgentsCarrying out multi-step tasks on its own10Claude Sonnet 41 of 1 test
- Long documentsFinding answers in very long texts10Claude Sonnet 41 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Sonnet 41 of 1 test
Agents, long documents and following instructions rest on a single test each.
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 2.5 Flash Lite costs 97% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Sonnet 4 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+48.3points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+41.1points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+26.6points ahead
Where Gemini 2.5 Flash Lite pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 32 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Sonnet 4
- SWE-bench VerifiedClaude Sonnet 4 by 41.172.731.6+41.1
- Terminal-Bench HardClaude Sonnet 4 by 26.631.14.5+26.6
- SciCodeClaude Sonnet 4 by 20.74019.3+20.7
ReasoningClaude Sonnet 4
- GPQA DiamondClaude Sonnet 4 by 15.277.762.5+15.2
- Humanity's Last ExamClaude Sonnet 4 by 3.910.76.8+3.9
- CritPttie0.30tie
FactsClaude Sonnet 4
- AA-Omniscience · Non-hallucinationClaude Sonnet 4 by 48.370.922.6+48.3
- Vectara HHEM hallucination ratelower is betterGemini 2.5 Flash Lite by 710.33.3+7
- AA-Omniscience · AccuracyClaude Sonnet 4 by 4.822.717.9+4.8
Images and chartsClaude Sonnet 4
Following instructionsClaude Sonnet 4
- IFBenchClaude Sonnet 4 by 4.854.749.9+4.8
Other results18 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.
- τ²-Bench Telecom (AA run)Claude Sonnet 4 by 46.264.618.4+46.2
- AA-OmniscienceClaude Sonnet 4 by 45.80.2-45.6+45.8
- Aider-PolyglotClaude Sonnet 4 by 4470.726.7+44
- LiveCodeBenchClaude Sonnet 4 by 34.868.533.7+34.8
- HarmBenchClaude Sonnet 4 by 319867+31
- Artificial Analysis Coding IndexClaude Sonnet 4 by 28.137.69.5+28.1
- AIR-Bench 2024Claude Sonnet 4 by 22.588.365.8+22.5
- AIME 2025Claude Sonnet 4 by 20.770.549.8+20.7
- AA Agentic IndexClaude Sonnet 4 by 11.517.66.1+11.5
- AA IntelligenceClaude Sonnet 4 by 10.418.98.5+10.4
- vectara_factual_consistencyGemini 2.5 Flash Lite by 789.796.7+7
- SimpleQAClaude Sonnet 4 by 5.215.910.7+5.2
- vectara_avg_summary_lengthClaude Sonnet 4 by 50.1 rating points145.895.7+50.1 rating
- simple_safety_testsClaude Sonnet 4 by 3.510096.5+3.5
- bbqClaude Sonnet 4 by 1.796.694.9+1.7
- XSTestGemini 2.5 Flash Lite by 1.296.697.8+1.2
- vectara_answer_ratetie98.699.5tie
- anthropic_red_teamtie99.298.7tie
Questions people ask
Which is better, Claude Sonnet 4 or Gemini 2.5 Flash Lite?
Claude Sonnet 4 wins all seven areas where both have results: coding, agents, reasoning, facts, images and charts, long documents and following instructions. Gemini 2.5 Flash Lite wins none, but costs 97% less.
Which is better for coding?
Claude Sonnet 4. It wins 3 of the 3 coding tests both models report; Gemini 2.5 Flash Lite wins none.
Which is cheaper?
Claude Sonnet 4 costs $3.00 per million input tokens and $15.00 per million output tokens; Gemini 2.5 Flash Lite costs $0.10 and $0.40. That makes Gemini 2.5 Flash Lite about 97% cheaper for the same work.
How do you compare the two?
We use the 32 benchmark tests both models have published scores on. The verdict counts the 14 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 18 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.