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Model comparison

Claude Mythos 5 vs GLM-5.1

Data verified

Head-to-head evidence from 4 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
16.2pts
← winning
67.74/100
4 category wins0 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); GLM-5.1 #18 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and GLM-5.1 share 4 comparable benchmark results. 4 of 8 categories are comparable. 11 results are unique to Claude Mythos 5; 32 to GLM-5.1.

Updated July 23, 2026
Shared results
4
Claude Mythos 5 only
11
GLM-5.1 only
32
Comparable categories
4 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. GLM-5.1 only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 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 Mythos 5 is clearly ahead on the BenchAlign aggregate, 83.93 to 67.74. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Mythos 5's sharpest advantage is in mathematics, where it averages 97.6 against 62. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 88% to 63.5%.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $1.40 input / $4.40 output per 1M tokens for GLM-5.1. That is roughly 11.4x on output cost alone. Claude Mythos 5 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 Mythos 5 and GLM-5.1
CategoryClaude Mythos 5ΔGLM-5.1
MathClaude Mythos 597.6Margin 35.6GLM-5.162.0
CodingClaude Mythos 589.7Margin 28.4GLM-5.161.3
AgenticClaude Mythos 587.0Margin 21.6GLM-5.165.4
KnowledgeClaude Mythos 568.5Margin 16.2GLM-5.152.3
MultimodalClaude Mythos 593.5MarginNo overlapGLM-5.1Not measured

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · GLM-5.1
  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 88%B 63.5%
    Winner: Claude Mythos 5Δ 24.5
    Terminal-Bench 2.0: Claude Mythos 5 scored 88%; GLM-5.1 scored 63.5%. Claude Mythos 5 wins this benchmark.
  2. SWE-bench Pro

    Coding
    Source ↗
    A 80.3%B 58.4%
    Winner: Claude Mythos 5Δ 21.9
    SWE-bench Pro: Claude Mythos 5 scored 80.3%; GLM-5.1 scored 58.4%. Claude Mythos 5 wins this benchmark.
  3. BrowseComp

    Agentic
    Source ↗
    A 88%B 68%
    Winner: Claude Mythos 5Δ 20
    BrowseComp: Claude Mythos 5 scored 88%; GLM-5.1 scored 68%. Claude Mythos 5 wins this benchmark.
  4. HLE

    Knowledge
    Source ↗
    A 64.5%B 52.3%
    Winner: Claude Mythos 5Δ 12.2
    HLE: Claude Mythos 5 scored 64.5%; GLM-5.1 scored 52.3%. Claude Mythos 5 wins this benchmark.

Operational comparison

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

MetricClaude Mythos 5GLM-5.1Comparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputGLM-5.1$1.4 input / $4.4 outputGLM-5.1 has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableGLM-5.1Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableGLM-5.1Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+GLM-5.1203KClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Mythos 5 wins
BenchmarkClaude Mythos 5GLM-5.1Result
Terminal-Bench 2.0Source 88%63.5%Claude Mythos 5 leads
OSWorld-VerifiedSource 85%Not comparable
BrowseCompSource 88%68%Claude Mythos 5 leads
ExploitGymSource 17.5%Not comparable
τ³-bench resultsSource 70.6%Not comparable
MCP AtlasSource 71.8%Not comparable
CyberGymSource 68.7%Not comparable
Claw-EvalSource 62.3%Not comparable
AA Agentic IndexSource 29.9%Not comparable
τ²-bench resultsSource 97.7%Not comparable
GDPval-AASource 37.8%Not comparable
Gert LabsSource 60.11%Not comparable
GDPval-AASource 1257Not comparable
ResearchClawBenchSource 18.2%Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5GLM-5.1Result
SWE-bench VerifiedSource 95.5%Not comparable
SWE-bench ProSource 80.3%58.4%Claude Mythos 5 leads
Terminal-Bench 2.0Source 88.0%Not comparable
NL2RepoSource 42.7%Not comparable
SWE-RebenchSource 62.7%Not comparable
Vibe Code BenchSource 31.46%Not comparable
AA Coding IndexSource 55.8%Not comparable
AA-SciCodeSource 43.8%Not comparable
Reasoning
BenchmarkClaude Mythos 5GLM-5.1Result
AA-LCRSource 62.3%Not comparable
CritPtSource 4.6%Not comparable
KnowledgeClaude Mythos 5 wins
BenchmarkClaude Mythos 5GLM-5.1Result
GPQASource 94.1%Not comparable
HLESource 64.5%52.3%Claude Mythos 5 leads
HLE w/o toolsSource 59%Not comparable
GPQA-DSource 86.2%Not comparable
Artificial Analysis Intelligence IndexSource 40.2%Not comparable
AA-GPQA DiamondSource 86.8%Not comparable
AA-HLESource 28.0%Not comparable
AA-Omniscience IndexSource 1.9%Not comparable
AA-Omniscience AccuracySource 24.2%Not comparable
AA-Omniscience Hallucination RateSource 29.4%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5GLM-5.1Result
USAMO 2026Source 97.6%Not comparable
AIME26Source 95.3%Not comparable
HMMT Nov 2025Source 94.0%Not comparable
HMMT Feb 2026Source 82.6%Not comparable
MMAnswerBenchSource 83.8%Not comparable
FrontierMath v2 (Tiers 1-3)Source 33.448%Not comparable
FrontierMath v2 (Tier 4)Source 12.500%Not comparable
Multilingual
BenchmarkClaude Mythos 5GLM-5.1Result
SWE MultilingualSource 92.2%Not comparable
Multimodal
BenchmarkClaude Mythos 5GLM-5.1Result
SWE-bench MultimodalSource 54.9%Not comparable
CharXivSource 93.5%Not comparable
CharXiv w/o toolsSource 88.9%Not comparable
Design Arena WebsiteSource 1305Not comparable
Inst. Following
BenchmarkClaude Mythos 5GLM-5.1Result
AA-IFBenchSource 76.3%Not comparable
Frequently Asked Questions (5)

Which is better, Claude Mythos 5 or GLM-5.1?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 67.74. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 88% and 63.5%.

Which is better for knowledge tasks, Claude Mythos 5 or GLM-5.1?

Claude Mythos 5 has the edge for knowledge tasks in this comparison, averaging 68.5 versus 52.3. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Mythos 5 or GLM-5.1?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 61.3. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, Claude Mythos 5 or GLM-5.1?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 62. GLM-5.1 stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Mythos 5 or GLM-5.1?

Claude Mythos 5 has the edge for agentic tasks in this comparison, averaging 87 versus 65.4. Inside this category, Terminal-Bench 2.0 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 Mythos 5
API / mo$45,000
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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Last updated: July 23, 2026

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