Claude Opus 4.8 vs GLM-5.1
Wins 6 of 7 areas
Coding · Agents · Reasoning · Facts · Math · Long documents
Wins 1 of 7 areas
Following instructions
Claude Opus 4.8 is the stronger all-rounder.GLM-5.1 is cheaper and better at following instructions.
Scores updated · 52 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.
- CodingWriting and fixing software70Claude Opus 4.87 of 7 tests
- AgentsCarrying out multi-step tasks on its own50Claude Opus 4.85 of 5 tests
- ReasoningHard problems that need careful thinking40Claude Opus 4.84 of 4 tests
- MathCompetition and research-level math30Claude Opus 4.83 of 4 tests · 1 tie
- FactsGetting facts right instead of making them up21Claude Opus 4.82 of 3 tests
- Long documentsFinding answers in very long texts10Claude Opus 4.81 of 1 test
- Following instructionsDoing exactly what it is asked01GLM-5.11 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-5.1 costs 81% 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 Claude Opus 4.8 pulls ahead
- Unpublished advanced math problemsFrontierMath Tiers 1-3 (v2)+43.2points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+25.1points ahead
- Command-line tasks in a real terminalTerminal-Bench 2.1+22.8points ahead
Where GLM-5.1 pulls ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+14.1points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+9.4points ahead
Every test, side by side
All 52 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.8
- Terminal-Bench 2.1Claude Opus 4.8 by 22.884.661.8+22.8
- Terminal-Bench HardClaude Opus 4.8 by 15.158.343.2+15.1
- SWE-bench VerifiedClaude Opus 4.8 by 12.488.676.2+12.4
- SWE-bench MultilingualClaude Opus 4.8 by 11.184.473.3+11.1
- SWE-bench ProClaude Opus 4.8 by 10.869.258.4+10.8
- SciCodeClaude Opus 4.8 by 9.654.444.8+9.6
- LMArena · WebDevClaude Opus 4.8 by 47 rating points15561509+47 rating
AgentsClaude Opus 4.8
- τ-Bench V3 · BankingClaude Opus 4.8 by 20.634.213.6+20.6
- Terminal-Bench 4.0Claude Opus 4.8 by 19.721.72+19.7
- GDPValClaude Opus 4.8 by 16.847.831+16.8
- MCP AtlasClaude Opus 4.8 by 10.482.271.8+10.4
- BrowseCompClaude Opus 4.8 by 584.379.3+5
ReasoningClaude Opus 4.8
- Humanity's Last ExamClaude Opus 4.8 by 18.648.730.1+18.6
- CritPtClaude Opus 4.8 by 16.320.94.6+16.3
- SimpleBenchClaude Opus 4.8 by 9.764.855.1+9.7
- GPQA DiamondClaude Opus 4.8 by 5.29286.8+5.2
FactsClaude Opus 4.8
- AA-Omniscience · AccuracyClaude Opus 4.8 by 25.148.823.7+25.1
- SimpleQA VerifiedClaude Opus 4.8 by 195334+19
- AA-Omniscience · Non-hallucinationGLM-5.1 by 9.460.770.1+9.4
MathClaude Opus 4.8
- FrontierMath Tiers 1-3 (v2)Claude Opus 4.8 by 43.28036.8+43.2
- HMMT Feb. 2026Claude Opus 4.8 by 12.995.582.6+12.9
- AIME 2026Claude Opus 4.8 by 4.710095.3+4.7
- IMOAnswerBenchtie83.583.8tie
Other results27 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.
- DeepSWEClaude Opus 4.8 by 405818+40
- GDPval-AA (Elo)Claude Opus 4.8 by 355 rating points18901535+355 rating
- AA-OmniscienceClaude Opus 4.8 by 27.928.80.8+27.9
- NL2RepoClaude Opus 4.8 by 2769.742.7+27
- Program BenchClaude Opus 4.8 by 2171.950.9+21
- Tool-DecathlonClaude Opus 4.8 by 19.259.940.7+19.2
- ToolathlonClaude Opus 4.8 by 19.259.940.7+19.2
- frontiermath_tier_4_v1Claude Opus 4.8 by 18.831.312.5+18.8
- Artificial Analysis Coding IndexClaude Opus 4.8 by 18.574.355.8+18.5
- AA Agentic IndexClaude Opus 4.8 by 17.442.625.2+17.4
- PostTrainBenchClaude Opus 4.8 by 17.137.220.1+17.1
- AA IntelligenceClaude Opus 4.8 by 15.741.826.1+15.7
- AgentWorldBench - MCPGLM-5.1 by 12.754.967.6+12.7
- AgentWorldBench - SearchClaude Opus 4.8 by 12.635.122.5+12.6
- AgentWorldBench - SWEClaude Opus 4.8 by 1264.152.1+12
- AgentWorldBench - TerminalClaude Opus 4.8 by 11.959.247.3+11.9
- CyberGymClaude Opus 4.8 by 10.178.868.7+10.1
- Finance Agent v2Claude Opus 4.8 by 9.153.944.8+9.1
- AgentWorldBench - OSClaude Opus 4.8 by 7.566.659.1+7.5
- LiveBenchClaude Opus 4.8 by 777.270.2+7
- HLE (with tools)Claude Opus 4.8 by 5.657.952.3+5.6
- Terminal-Bench 2.0Claude Opus 4.8 by 5.674.669+5.6
- AgentWorldBench - OverallClaude Opus 4.8 by 5.356.651.3+5.3
- τ²-Bench Telecom (AA run)GLM-5.1 by 3.394.497.7+3.3
- AgentWorldBench - WebClaude Opus 4.8 by 3.254.751.5+3.2
- HMMT Nov. 2025Claude Opus 4.8 by 2.596.594+2.5
- AgentWorldBench - AndroidClaude Opus 4.8 by 2.461.559.1+2.4
Questions people ask
Which is better, Claude Opus 4.8 or GLM-5.1?
Claude Opus 4.8 wins six of the seven areas where both have results: coding, agents, reasoning, facts, math and long documents. GLM-5.1 wins following instructions, and costs 81% less.
Which is better for coding?
Claude Opus 4.8. It wins 7 of the 7 coding tests both models report; GLM-5.1 wins none.
Which is cheaper?
Claude Opus 4.8 costs $5.00 per million input tokens and $25.00 per million output tokens; GLM-5.1 costs $1.38 and $4.40. That makes GLM-5.1 about 81% cheaper for the same work.
How do you compare the two?
We use the 52 benchmark tests both models have published scores on. The verdict counts the 25 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 27 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.