Claude Fable 5 vs GLM-5.3-Flash
Wins 7 of 8 areas
Coding · Reasoning · Facts · Images and charts · Math · Long documents · Following instructions
Wins 1 of 8 areas
Agents
Claude Fable 5 is the stronger all-rounder.GLM-5.3-Flash is cheaper and better at agents.
Scores updated · 33 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 thinking50Claude Fable 55 of 5 tests
- CodingWriting and fixing software40Claude Fable 54 of 5 tests · 1 tie
- MathCompetition and research-level math30Claude Fable 53 of 3 tests
- FactsGetting facts right instead of making them up21Claude Fable 52 of 3 tests
- Images and chartsUnderstanding pictures, charts and video10Claude Fable 51 of 1 test
- Long documentsFinding answers in very long texts10Claude Fable 51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Fable 51 of 1 test
- AgentsCarrying out multi-step tasks on its own12GLM-5.3-Flash2 of 3 tests
Images and charts, 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 99% 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 Fable 5 pulls ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+73.1points ahead
- Short factual questions, answered correctlySimpleQA Verified+38.7points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+37.9points ahead
Where GLM-5.3-Flash pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+36points ahead
- Customer-service tasks in a simulated bankτ-Bench V3 · Banking+9.1points ahead
- Real work tasks from 44 professionsGDPVal+1.7points 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 Fable 5
- SciCodeClaude Fable 5 by 9.46151.6+9.4
- LiveBench · CodingClaude Fable 5 by 78679+7
- LiveBench · Agentic CodingClaude Fable 5 by 5.462.256.8+5.4
- LMArena · WebDevClaude Fable 5 by 20 rating points16251605+20 rating
- Terminal-Bench 2.1tie84.684.3tie
AgentsGLM-5.3-Flash
- Terminal-Bench 4.0Claude Fable 5 by 9.642.432.8+9.6
- τ-Bench V3 · BankingGLM-5.3-Flash by 9.138.147.2+9.1
- GDPValGLM-5.3-Flash by 1.755.557.2+1.7
ReasoningClaude Fable 5
- ARC-AGI-2Claude Fable 5 by 23.489.265.8+23.4
- Humanity's Last ExamClaude Fable 5 by 15.655.539.9+15.6
- CritPtClaude Fable 5 by 13.228.615.4+13.2
- LiveBench · ReasoningClaude Fable 5 by 12.189.777.6+12.1
- GPQA DiamondClaude Fable 5 by 1.492.691.2+1.4
FactsClaude Fable 5
- SimpleQA VerifiedClaude Fable 5 by 38.770.732+38.7
- AA-Omniscience · AccuracyClaude Fable 5 by 37.965.327.5+37.9
- AA-Omniscience · Non-hallucinationGLM-5.3-Flash by 3636.472.4+36
Images and chartsClaude Fable 5
- LMArena · VisionClaude Fable 5 by 28 rating points13241296+28 rating
MathClaude Fable 5
- FrontierMath Tier 4Claude Fable 5 by 73.190.217.1+73.1
- FrontierMath Tiers 1-3 (v2)Claude Fable 5 by 31.28755.8+31.2
- LiveBench · MathematicsClaude Fable 5 by 14.89681.2+14.8
Following instructionsClaude Fable 5
- LiveBench · Instruction FollowingClaude Fable 5 by 2375.852.8+23
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.
- AA-OmniscienceClaude Fable 5 by 35.843.37.5+35.8
- ToolathlonGLM-5.3-Flash by 16.761.778.4+16.7
- livebench_languageClaude Fable 5 by 13.490.777.3+13.4
- AA IntelligenceClaude Fable 5 by 7.849.641.8+7.8
- ARC-AGI-1Claude Fable 5 by 7.598.591+7.5
- DeepSWE 1.1Claude Fable 5 by 6.67063.4+6.6
- Artificial Analysis Coding IndexClaude Fable 5 by 576.571.5+5
- OfficeQA ProGLM-5.3-Flash by 4.557.962.4+4.5
- livebench_data_analysisClaude Fable 5 by 4.180.576.4+4.1
- Agents' Last Examtie25.726.3tie
- AA Agentic Indextie5151.2tie
Questions people ask
Which is better, Claude Fable 5 or GLM-5.3-Flash?
Claude Fable 5 wins seven of the eight areas we test: coding, reasoning, facts, images and charts, math, long documents and following instructions. GLM-5.3-Flash wins agents, and costs 99% less.
Which is better for coding?
Claude Fable 5. It wins 4 of the 5 coding tests both models report; GLM-5.3-Flash wins none, and 1 is a tie.
Which is cheaper?
Claude Fable 5 costs $10.00 per million input tokens and $50.00 per million output tokens; GLM-5.3-Flash costs $0.15 and $0.50. That makes GLM-5.3-Flash about 99% 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 22 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.