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Model comparison

Claude Opus 4.8 vs GLM-5.1

Data verified

Head-to-head evidence from 26 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

78.34/100
Margin
10.6pts
← winning
67.74/100
3 category wins1 category wins

Public leaderboard positions: Claude Opus 4.8 #5 (Supported); GLM-5.1 #18 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.8 and GLM-5.1 share 26 comparable benchmark results. 4 of 8 categories are comparable. 27 results are unique to Claude Opus 4.8; 10 to GLM-5.1.

Updated July 23, 2026
Shared results
26
Claude Opus 4.8 only
27
GLM-5.1 only
10
Comparable categories
4 / 8

Pick Claude Opus 4.8 if you want the stronger benchmark profile. GLM-5.1 only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 26 shared benchmark results across 7 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Opus 4.8 is clearly ahead on the BenchAlign aggregate, 78.34 to 67.74. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.8's sharpest advantage is in coding, where it averages 81.1 against 61.3. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 31.250% to 12.500%. GLM-5.1 does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.8 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $1.40 input / $4.40 output per 1M tokens for GLM-5.1. That is roughly 5.7x on output cost alone. Claude Opus 4.8 gives you the larger context window at 1M, compared with 203K for GLM-5.1.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Opus 4.8 and GLM-5.1
CategoryClaude Opus 4.8ΔGLM-5.1
CodingClaude Opus 4.881.1Margin← 19.8GLM-5.161.3
AgenticClaude Opus 4.880.3Margin← 14.9GLM-5.165.4
KnowledgeClaude Opus 4.862.7Margin← 10.4GLM-5.152.3
MathClaude Opus 4.853.9Margin→ 8.1GLM-5.162.0
MultimodalClaude Opus 4.877.0MarginNo overlapGLM-5.1Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Opus 4.8B · GLM-5.1

  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 31.250%B 12.500%
    Winner: Claude Opus 4.8Δ 18.8
    FrontierMath v2 (Tier 4): Claude Opus 4.8 scored 31.250%; GLM-5.1 scored 12.500%. Claude Opus 4.8 wins this benchmark.

  2. BrowseComp

    Agentic
    Source ↗
    A 84.3%B 68%
    Winner: Claude Opus 4.8Δ 16.3
    BrowseComp: Claude Opus 4.8 scored 84.3%; GLM-5.1 scored 68%. Claude Opus 4.8 wins this benchmark.

  3. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 47.241%B 33.448%
    Winner: Claude Opus 4.8Δ 13.8
    FrontierMath v2 (Tiers 1-3): Claude Opus 4.8 scored 47.241%; GLM-5.1 scored 33.448%. Claude Opus 4.8 wins this benchmark.

  4. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 74.6%B 63.5%
    Winner: Claude Opus 4.8Δ 11.1
    Terminal-Bench 2.0: Claude Opus 4.8 scored 74.6%; GLM-5.1 scored 63.5%. Claude Opus 4.8 wins this benchmark.

  5. SWE-bench Pro

    Coding
    Source ↗
    A 69.2%B 58.4%
    Winner: Claude Opus 4.8Δ 10.8
    SWE-bench Pro: Claude Opus 4.8 scored 69.2%; GLM-5.1 scored 58.4%. Claude Opus 4.8 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Opus 4.8GLM-5.1Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.8$5 input / $25 outputGLM-5.1$1.4 input / $4.4 outputGLM-5.1 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.8Not availableGLM-5.1Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.8Not availableGLM-5.1Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.81MGLM-5.1203KClaude Opus 4.8 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8GLM-5.1Result
Terminal-Bench 2.0Source 74.6%63.5%Claude Opus 4.8 leads
BrowseCompSource 84.3%68%Claude Opus 4.8 leads
DeepSearchQASource 93.1%—Not comparable
OSWorld-VerifiedSource 83.4%—Not comparable
Finance Agent v2Source 53.9%—Not comparable
GDPval-AASource 15941257Claude Opus 4.8 leads
MCP AtlasSource 82.2%71.8%Claude Opus 4.8 leads
ToolathlonSource 59.9%—Not comparable
Gert LabsSource 72.97%60.11%Claude Opus 4.8 leads
AA Agentic IndexSource 47.2%29.9%Claude Opus 4.8 leads
τ²-bench resultsSource 94.4%97.7%GLM-5.1 leads
GDPval-AASource 54.7%37.8%Claude Opus 4.8 leads
ResearchClawBenchSource 21.1%18.2%Claude Opus 4.8 leads
OSWorld 2.0Source 20.6%—Not comparable
AA BriefcaseSource 1347—Not comparable
AA AutomationBenchSource 48.5%—Not comparable
AA EnterpriseOps-GymSource 44.0%—Not comparable
AA Harvey LABSource 91.1%—Not comparable
AA Tau3 BankingSource 27.6%—Not comparable
terminalBenchHardSource 58.3%—Not comparable
aaTerminalBench21Source 84.6%—Not comparable
τ³-bench resultsSource —70.6%Not comparable
CyberGymSource —68.7%Not comparable
Claw-EvalSource —62.3%Not comparable
CodingClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8GLM-5.1Result
SWE-bench VerifiedSource 88.6%—Not comparable
SWE-bench ProSource 69.2%58.4%Claude Opus 4.8 leads
SWE MultilingualSource 84.4%—Not comparable
SWE MultimodalSource 38.4%—Not comparable
Terminal-Bench 2.0Source 74.6%—Not comparable
cursorBench31Source 58.4%—Not comparable
cursorBench32Source 62.3%—Not comparable
AA Coding IndexSource 74.3%55.8%Claude Opus 4.8 leads
AA-SciCodeSource 53.5%43.8%Claude Opus 4.8 leads
FrontierCode 1.1 MainSource 46.5%—Not comparable
NL2RepoSource —42.7%Not comparable
SWE-RebenchSource —62.7%Not comparable
Vibe Code BenchSource —31.46%Not comparable
Reasoning
BenchmarkClaude Opus 4.8GLM-5.1Result
AA-LCRSource 67.7%62.3%Claude Opus 4.8 leads
CritPtSource 20.9%4.6%Claude Opus 4.8 leads
KnowledgeClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8GLM-5.1Result
GPQASource 93.6%—Not comparable
GPQA-DSource 93.6%86.2%Claude Opus 4.8 leads
HLESource 57.9%52.3%Claude Opus 4.8 leads
HLE w/o toolsSource 49.8%—Not comparable
Artificial Analysis Intelligence IndexSource 55.7%40.2%Claude Opus 4.8 leads
AA-GPQA DiamondSource 92.0%86.8%Claude Opus 4.8 leads
AA-HLESource 45.7%28.0%Claude Opus 4.8 leads
AA-Omniscience IndexSource 27.4%1.9%Claude Opus 4.8 leads
AA-Omniscience AccuracySource 46.6%24.2%Claude Opus 4.8 leads
AA-Omniscience Hallucination RateSource 35.9%29.4%GLM-5.1 leads
MathGLM-5.1 wins
BenchmarkClaude Opus 4.8GLM-5.1Result
USAMO 2026Source 96.7%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 47.241%33.448%Claude Opus 4.8 leads
FrontierMath v2 (Tier 4)Source 31.250%12.500%Claude Opus 4.8 leads
AIME26Source —95.3%Not comparable
HMMT Nov 2025Source —94.0%Not comparable
HMMT Feb 2026Source —82.6%Not comparable
MMAnswerBenchSource —83.8%Not comparable
Multilingual
BenchmarkClaude Opus 4.8GLM-5.1Result
INCLUDESource 87.6%—Not comparable
Multimodal
BenchmarkClaude Opus 4.8GLM-5.1Result
OfficeQA ProSource 66.2%—Not comparable
ScreenSpot ProSource 87.9%—Not comparable
CharXivSource 89.9%—Not comparable
CharXiv w/o toolsSource 80.5%—Not comparable
Design Arena WebsiteSource 12701305GLM-5.1 leads
Inst. Following
BenchmarkClaude Opus 4.8GLM-5.1Result
AA-IFBenchSource 62.2%76.3%GLM-5.1 leads
Frequently Asked Questions (5)

Which is better, Claude Opus 4.8 or GLM-5.1?

Claude Opus 4.8 is ahead on BenchLM's BenchAlign leaderboard, 78.34 to 67.74. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 31.250% and 12.500%.

Which is better for knowledge tasks, Claude Opus 4.8 or GLM-5.1?

Claude Opus 4.8 has the edge for knowledge tasks in this comparison, averaging 62.7 versus 52.3. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Opus 4.8 or GLM-5.1?

Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 61.3. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.

Which is better for math, Claude Opus 4.8 or GLM-5.1?

GLM-5.1 has the edge for math in this comparison, averaging 62 versus 53.9. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Opus 4.8 or GLM-5.1?

Claude Opus 4.8 has the edge for agentic tasks in this comparison, averaging 80.3 versus 65.4. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Claude Opus 4.8
API / mo$22,500
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
GLM-5.1
API / mo$4,350
Self-host / mo$18,221
Break-even264M/day
Model the full break-even

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