Gemini 3.5 Flash vs GLM-5.1
Wins 4 of 7 areas
Agents · Reasoning · Facts · Math
Wins 1 of 7 areas
Coding
Gemini 3.5 Flash wins more areas, narrowly.GLM-5.1 is cheaper and better at coding.
Both rank among the ten best models we track in following instructions.
Scores updated · 34 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.
- AgentsCarrying out multi-step tasks on its own40Gemini 3.5 Flash4 of 5 tests · 1 tie
- ReasoningHard problems that need careful thinking40Gemini 3.5 Flash4 of 4 tests
- MathCompetition and research-level math20Gemini 3.5 Flash2 of 3 tests · 1 tie
- FactsGetting facts right instead of making them up21Gemini 3.5 Flash2 of 3 tests
- CodingWriting and fixing software23GLM-5.13 of 5 tests
- Long documentsFinding answers in very long texts00Even0 each · 1 tie
- Following instructionsDoing exactly what it is asked00Even0 each · 1 tie
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.
GLM-5.1 costs 45% 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
- Short factual questions, answered correctlySimpleQA Verified+32.2points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+27.7points ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+26points ahead
Where GLM-5.1 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+32.3points ahead
- Long, multi-file coding tasks in real codebasesSWE-bench Pro+3.3points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+2.3points ahead
Every test, side by side
All 34 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGLM-5.1
- Terminal-Bench 2.1Gemini 3.5 Flash by 16.978.761.8+16.9
- SciCodeGemini 3.5 Flash by 9.153.944.8+9.1
- SWE-bench ProGLM-5.1 by 3.355.158.4+3.3
- Terminal-Bench HardGLM-5.1 by 2.340.943.2+2.3
- LMArena · WebDevGLM-5.1 by 10 rating points14991509+10 rating
AgentsGemini 3.5 Flash
- τ-Bench V3 · BankingGemini 3.5 Flash by 18.632.213.6+18.6
- MCP AtlasGemini 3.5 Flash by 11.883.671.8+11.8
- Terminal-Bench 4.0Gemini 3.5 Flash by 4.66.62+4.6
- GDPValGemini 3.5 Flash by 4.235.231+4.2
- AA IT-Bench SREtie40.340.3tie
ReasoningGemini 3.5 Flash
- SimpleBenchGemini 3.5 Flash by 21.676.755.1+21.6
- Humanity's Last ExamGemini 3.5 Flash by 12.642.730.1+12.6
- CritPtGemini 3.5 Flash by 8.513.14.6+8.5
- GPQA DiamondGemini 3.5 Flash by 5.492.286.8+5.4
FactsGemini 3.5 Flash
- AA-Omniscience · Non-hallucinationGLM-5.1 by 32.337.870.1+32.3
- SimpleQA VerifiedGemini 3.5 Flash by 32.266.234+32.2
- AA-Omniscience · AccuracyGemini 3.5 Flash by 27.751.423.7+27.7
MathGemini 3.5 Flash
- FrontierMath Tiers 1-3 (v2)Gemini 3.5 Flash by 2662.836.8+26
- HMMT Feb. 2026Gemini 3.5 Flash by 12.995.582.6+12.9
- AIME 2026tie9595.3tie
Other results12 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-OmniscienceGemini 3.5 Flash by 20.321.20.8+20.3
- DeepSWEGemini 3.5 Flash by 193718+19
- ToolathlonGemini 3.5 Flash by 15.856.540.7+15.8
- Artificial Analysis Coding IndexGemini 3.5 Flash by 14.370.155.8+14.3
- Finance Agent v2Gemini 3.5 Flash by 13.157.944.8+13.1
- GDPval-AA (Elo)Gemini 3.5 Flash by 121 rating points16561535+121 rating
- Terminal-Bench 2.0Gemini 3.5 Flash by 7.276.269+7.2
- AA IntelligenceGemini 3.5 Flash by 6.532.626.1+6.5
- LiveBenchGemini 3.5 Flash by 4.87570.2+4.8
- τ²-Bench Telecom (AA run)GLM-5.1 by 2.495.397.7+2.4
- AA Agentic IndexGemini 3.5 Flash by 2.127.325.2+2.1
- frontiermath_tier_4_v1Gemini 3.5 Flash by 2.114.612.5+2.1
Questions people ask
Which is better, Gemini 3.5 Flash or GLM-5.1?
Gemini 3.5 Flash wins four of the seven areas where both have results: agents, reasoning, facts and math. GLM-5.1 wins coding, and costs 45% less. They are level on long documents and following instructions.
Which is better for coding?
GLM-5.1. It wins 3 of the 5 coding tests both models report; Gemini 3.5 Flash wins 2.
Which is cheaper?
Gemini 3.5 Flash costs $1.50 per million input tokens and $9.00 per million output tokens; GLM-5.1 costs $1.38 and $4.40. That makes GLM-5.1 about 45% cheaper for the same work.
How do you compare the two?
We use the 34 benchmark tests both models have published scores on. The verdict counts the 22 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 12 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.