Gemini 2.5 Flash vs GPT-4o
Wins 7 of 7 areas
Coding · Agents · Reasoning · Facts · Images and charts · Long documents · Following instructions
Wins 0 of 7 areas
—
Gemini 2.5 Flash is the stronger all-rounder.
Scores updated · 38 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.
- ReasoningHard problems that need careful thinking40Gemini 2.5 Flash4 of 4 tests
- Images and chartsUnderstanding pictures, charts and video20Gemini 2.5 Flash2 of 2 tests
- CodingWriting and fixing software21Gemini 2.5 Flash2 of 3 tests
- FactsGetting facts right instead of making them up21Gemini 2.5 Flash2 of 3 tests
- AgentsCarrying out multi-step tasks on its own10Gemini 2.5 Flash1 of 1 test
- Long documentsFinding answers in very long texts10Gemini 2.5 Flash1 of 1 test
- Following instructionsDoing exactly what it is asked10Gemini 2.5 Flash1 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 costs 86% 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 Gemini 2.5 Flash pulls ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+27.2points ahead
- Graduate-level biology, physics and chemistry questionsGPQA Diamond+26.4points ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+14.3points ahead
Where GPT-4o pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+37.4points ahead
- Code for real scientific research problemsSciCode+4.2points ahead
Every test, side by side
All 38 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGemini 2.5 Flash
- SWE-bench VerifiedGemini 2.5 Flash by 27.260.433.2+27.2
- Terminal-Bench HardGemini 2.5 Flash by 5.313.68.3+5.3
- SciCodeGPT-4o by 4.229.133.3+4.2
ReasoningGemini 2.5 Flash
- GPQA DiamondGemini 2.5 Flash by 26.47952.6+26.4
- Humanity's Last ExamGemini 2.5 Flash by 10.312.11.8+10.3
- ARC-AGI-2Gemini 2.5 Flash by 2.52.50+2.5
- CritPtGemini 2.5 Flash by 1.11.10+1.1
FactsGemini 2.5 Flash
- AA-Omniscience · Non-hallucinationGPT-4o by 37.424.762.1+37.4
- AA-Omniscience · AccuracyGemini 2.5 Flash by 2.325.923.7+2.3
- Vectara HHEM hallucination ratelower is betterGemini 2.5 Flash by 1.87.89.6+1.8
Images and chartsGemini 2.5 Flash
Following instructionsGemini 2.5 Flash
- IFBenchGemini 2.5 Flash by 14.350.336+14.3
Other results23 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.
- AIME 2024Gemini 2.5 Flash by 7382.39.3+73
- AIME 2025Gemini 2.5 Flash by 60.37211.7+60.3
- livecodebench_mediumGemini 2.5 Flash by 50.482.532.1+50.4
- livecodebench_hardGemini 2.5 Flash by 43.848.34.5+43.8
- LiveCodeBenchGemini 2.5 Flash by 37.976.238.3+37.9
- Aider-PolyglotGemini 2.5 Flash by 31.261.930.7+31.2
- ARC-AGI-1Gemini 2.5 Flash by 27.832.34.5+27.8
- HarmBenchGPT-4o by 20.362.682.9+20.3
- AA-OmniscienceGPT-4o by 19.3-29.8-10.5+19.3
- livecodebench_easyGemini 2.5 Flash by 16.699.182.5+16.6
- SimpleQAGPT-4o by 11.326.938.2+11.3
- AA Agentic IndexGemini 2.5 Flash by 10.418.88.4+10.4
- AIR-Bench 2024Gemini 2.5 Flash by 6.368.762.4+6.3
- AA IntelligenceGemini 2.5 Flash by 5.813.17.3+5.8
- vectara_answer_rateGemini 2.5 Flash by 5.29993.8+5.2
- τ²-Bench Telecom (AA run)Gemini 2.5 Flash by 2.731.628.9+2.7
- bbqGemini 2.5 Flash by 2.697.795.1+2.6
- Artificial Analysis Coding IndexGPT-4o by 222.224.2+2
- vectara_factual_consistencyGemini 2.5 Flash by 1.892.290.4+1.8
- XSTestGemini 2.5 Flash by 1.598.897.3+1.5
- vectara_avg_summary_lengthGemini 2.5 Flash by 14.9 rating points101.586.6+14.9 rating
- simple_safety_teststie9898.5tie
- anthropic_red_teamtie98.899.1tie
Questions people ask
Which is better, Gemini 2.5 Flash or GPT-4o?
Gemini 2.5 Flash wins all seven areas where both have results: coding, agents, reasoning, facts, images and charts, long documents and following instructions. GPT-4o wins none.
Which is better for coding?
Gemini 2.5 Flash. It wins 2 of the 3 coding tests both models report; GPT-4o wins 1.
Which is cheaper?
Gemini 2.5 Flash costs $0.30 per million input tokens and $2.50 per million output tokens; GPT-4o costs $5.00 and $15.00. That makes Gemini 2.5 Flash about 86% cheaper for the same work.
How do you compare the two?
We use the 38 benchmark tests both models have published scores on. The verdict counts the 15 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 23 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.