Claude Sonnet 5 vs GLM-5.3-Flash
Wins 6 of 8 areas
Coding · Reasoning · Facts · Math · Long documents · Following instructions
Wins 2 of 8 areas
Agents · Images and charts
Claude Sonnet 5 is the stronger all-rounder.GLM-5.3-Flash is cheaper and better at images and charts.
Scores updated · 35 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 thinking30Claude Sonnet 53 of 4 tests · 1 tie
- MathCompetition and research-level math30Claude Sonnet 53 of 3 tests
- CodingWriting and fixing software32Claude Sonnet 53 of 5 tests
- FactsGetting facts right instead of making them up21Claude Sonnet 52 of 3 tests
- Long documentsFinding answers in very long texts10Claude Sonnet 51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Sonnet 51 of 1 test
- Images and chartsUnderstanding pictures, charts and video02GLM-5.3-Flash2 of 2 tests
- AgentsCarrying out multi-step tasks on its own23GLM-5.3-Flash3 of 5 tests
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-5.3-Flash costs 95% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Claude Sonnet 5 pulls ahead
- Completes tasks by operating a computer desktopOSWorld-Verified+66.4points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+12.6points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+12.2points ahead
Where GLM-5.3-Flash pulls ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+18.7points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+11.8points ahead
- Customer-service tasks in a simulated bankτ-Bench V3 · Banking+9.9points ahead
Every test, side by side
All 35 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Sonnet 5
- LMArena · WebDevGLM-5.3-Flash by 70 rating points15391609+70 rating
- Terminal-Bench 2.1GLM-5.3-Flash by 3.880.584.3+3.8
- SciCodeClaude Sonnet 5 by 2.754.351.6+2.7
- LiveBench · Agentic CodingClaude Sonnet 5 by 2.659.456.8+2.6
- LiveBench · CodingClaude Sonnet 5 by 1.780.779+1.7
AgentsGLM-5.3-Flash
- OSWorld-VerifiedClaude Sonnet 5 by 66.481.214.8+66.4
- Terminal-Bench 4.0GLM-5.3-Flash by 18.714.132.8+18.7
- τ-Bench V3 · BankingGLM-5.3-Flash by 9.937.347.2+9.9
- GDPValGLM-5.3-Flash by 948.257.2+9
- BrowseCompClaude Sonnet 5 by 8.784.776+8.7
ReasoningClaude Sonnet 5
- LiveBench · ReasoningClaude Sonnet 5 by 11.188.777.6+11.1
- CritPtClaude Sonnet 5 by 1.516.915.4+1.5
- Humanity's Last ExamClaude Sonnet 5 by 1.441.339.9+1.4
- GPQA Diamondtie91.191.2tie
FactsClaude Sonnet 5
- AA-Omniscience · AccuracyClaude Sonnet 5 by 12.64027.5+12.6
- AA-Omniscience · Non-hallucinationGLM-5.3-Flash by 11.860.672.4+11.8
- SimpleQA VerifiedClaude Sonnet 5 by 1.733.732+1.7
Images and chartsGLM-5.3-Flash
- LMArena · VisionGLM-5.3-Flash by 23 rating points12721295+23 rating
- CharXiv (RQ)GLM-5.3-Flash by 1.188.389.4+1.1
MathClaude Sonnet 5
- FrontierMath Tier 4Claude Sonnet 5 by 12.229.317.1+12.2
- LiveBench · MathematicsClaude Sonnet 5 by 11.792.981.2+11.7
- FrontierMath Tiers 1-3 (v2)Claude Sonnet 5 by 9.865.655.8+9.8
Following instructionsClaude Sonnet 5
- LiveBench · Instruction FollowingClaude Sonnet 5 by 11.163.952.8+11.1
Other results11 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.
- GDP (Surge AI)Claude Sonnet 5 by 66.281.615.4+66.2
- ToolathlonGLM-5.3-Flash by 24.154.378.4+24.1
- GDPval-AA 2.1GLM-5.3-Flash by 200 rating points14491649+200 rating
- DeepSWE 1.1GLM-5.3-Flash by 9.45463.4+9.4
- AA-OmniscienceClaude Sonnet 5 by 916.47.5+9
- AA Agentic IndexGLM-5.3-Flash by 6.944.351.2+6.9
- livebench_data_analysisGLM-5.3-Flash by 4.771.776.4+4.7
- AA IntelligenceGLM-5.3-Flash by 3.638.241.8+3.6
- OfficeQA ProGLM-5.3-Flash by 359.462.4+3
- livebench_languageGLM-5.3-Flash by 2.37577.3+2.3
- Artificial Analysis Coding Indextie71.571.5tie
Questions people ask
Which is better, Claude Sonnet 5 or GLM-5.3-Flash?
Claude Sonnet 5 wins six of the eight areas we test: coding, reasoning, facts, math, long documents and following instructions. GLM-5.3-Flash wins agents and images and charts, and costs 95% less.
Which is better for coding?
Claude Sonnet 5. It wins 3 of the 5 coding tests both models report; GLM-5.3-Flash wins 2.
Which is cheaper?
Claude Sonnet 5 costs $2.00 per million input tokens and $10.00 per million output tokens; GLM-5.3-Flash costs $0.15 and $0.50. That makes GLM-5.3-Flash about 95% cheaper for the same work.
How do you compare the two?
We use the 35 benchmark tests both models have published scores on. The verdict counts the 24 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 11 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.