GLM-5.3 vs Claude Sonnet 5.5
Wins 1 of 7 areas
Following instructions
Wins 6 of 7 areas
Coding · Agents · Reasoning · Facts · Math · Long documents
Claude Sonnet 5.5 is the stronger all-rounder.GLM-5.3 is cheaper and better at following instructions.
Scores updated · 33 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 thinking04Claude Sonnet 5.54 of 4 tests
- MathCompetition and research-level math03Claude Sonnet 5.53 of 3 tests
- CodingWriting and fixing software13Claude Sonnet 5.53 of 4 tests
- AgentsCarrying out multi-step tasks on its own02Claude Sonnet 5.52 of 2 tests
- FactsGetting facts right instead of making them up12Claude Sonnet 5.52 of 3 tests
- Long documentsFinding answers in very long texts01Claude Sonnet 5.51 of 1 test
- Following instructionsDoing exactly what it is asked10GLM-5.31 of 1 test
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 costs 52% 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 5.5 pulls ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+51.2points ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+21.7points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+20.1points ahead
Where GLM-5.3 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+17.4points ahead
- Follows detailed instructions exactlyLiveBench · Instruction Following+12.5points ahead
- Fixes real GitHub issues, working as an agentLiveBench · Agentic Coding+4.6points ahead
Every test, side by side
All 33 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Sonnet 5.5
- LMArena · WebDevClaude Sonnet 5.5 by 152 rating points16221774+152 rating
- LiveBench · CodingClaude Sonnet 5.5 by 12.47991.4+12.4
- LiveBench · Agentic CodingGLM-5.3 by 4.660.956.3+4.6
- SciCodeClaude Sonnet 5.5 by 25961+2
AgentsClaude Sonnet 5.5
- Terminal-Bench 4.0Claude Sonnet 5.5 by 21.741.963.6+21.7
- GDPValClaude Sonnet 5.5 by 9.457.566.9+9.4
ReasoningClaude Sonnet 5.5
- Humanity's Last ExamClaude Sonnet 5.5 by 12.742.355+12.7
- CritPtClaude Sonnet 5.5 by 12.319.131.4+12.3
- SimpleBenchClaude Sonnet 5.5 by 9.766.275.9+9.7
- LiveBench · ReasoningClaude Sonnet 5.5 by 5.885.891.6+5.8
FactsClaude Sonnet 5.5
- AA-Omniscience · AccuracyClaude Sonnet 5.5 by 20.133.954+20.1
- AA-Omniscience · Non-hallucinationGLM-5.3 by 17.470.453+17.4
- SimpleQA VerifiedClaude Sonnet 5.5 by 5.54146.5+5.5
MathClaude Sonnet 5.5
- FrontierMath Tier 4Claude Sonnet 5.5 by 51.229.380.5+51.2
- FrontierMath Tiers 1-3 (v2)Claude Sonnet 5.5 by 2068.888.8+20
- LiveBench · MathematicsClaude Sonnet 5.5 by 8.287.996.1+8.2
Following instructionsGLM-5.3
- LiveBench · Instruction FollowingGLM-5.3 by 12.569.356.8+12.5
Other results15 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.
- Program BenchClaude Sonnet 5.5 by 60.71979.7+60.7
- Terminal-Bench-Science 0.1Claude Sonnet 5.5 by 43.89.553.3+43.8
- HLE-DiamondClaude Sonnet 5.5 by 35.417.953.3+35.4
- Terminal-Bench 4.0Claude Sonnet 5.5 by 28.841.870.6+28.8
- CritPt v2 HardClaude Sonnet 5.5 by 25.533.559+25.5
- AA-OmniscienceClaude Sonnet 5.5 by 1814.332.3+18
- GDP (Surge AI)Claude Sonnet 5.5 by 14.611.225.8+14.6
- AA IntelligenceClaude Sonnet 5.5 by 11.244.856+11.2
- livebench_data_analysisGLM-5.3 by 10.770.259.5+10.7
- HealthBench ProfessionalClaude Sonnet 5.5 by 10.252.863+10.2
- HealthBenchClaude Sonnet 5.5 by 7.654.562.1+7.6
- Toolathlon VerifiedClaude Sonnet 5.5 by 4.87377.8+4.8
- DeepSWE 1.1Claude Sonnet 5.5 by 4.166.971+4.1
- HLE (with tools)Claude Sonnet 5.5 by 262.564.5+2
- livebench_languageGLM-5.3 by 1.979.978+1.9
Questions people ask
Which is better, GLM-5.3 or Claude Sonnet 5.5?
Claude Sonnet 5.5 wins six of the seven areas where both have results: coding, agents, reasoning, facts, math and long documents. GLM-5.3 wins following instructions, and costs 52% less.
Which is better for coding?
Claude Sonnet 5.5. It wins 3 of the 4 coding tests both models report; GLM-5.3 wins 1.
Which is cheaper?
GLM-5.3 costs $1.40 per million input tokens and $4.40 per million output tokens; Claude Sonnet 5.5 costs $2.00 and $10.00. That makes GLM-5.3 about 52% cheaper for the same work.
How do you compare the two?
We use the 33 benchmark tests both models have published scores on. The verdict counts the 18 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 15 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.