ZMIME
Comparison · 3 models · Updated Oct 4, 2026

Claude Sonnet 4.6 vs GLM-5.1 vs GPT-5.2

Too close to call on our weighted score (Claude Sonnet 4.6 62, GPT-5.2 61, GLM-5.1 57). The right pick depends on what you value most.

  1. Anthropic

    Claude Sonnet 4.6

    Released Feb 17, 2026

    62/100
    • ECI152.3
    • Price$3.00 / $15.00
    • Context1M
    Full specs Remove Claude Sonnet 4.6

  2. Z.ai (Zhipu)

    GLM-5.1

    Released Apr 7, 2026

    57/100
    • ECI149.9
    • Price$1.40 / $4.40
    • Context200K
    Full specs Remove GLM-5.1

  3. OpenAI

    GPT-5.2

    Released Dec 11, 2025

    61/100
    • ECI153.5
    • Price$1.75 / $14.00
    • Context400K
    Full specs Remove GPT-5.2
01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, GLM-5.1 57/100), so choose by what matters most for your work: GPT-5.2 for raw capability, GLM-5.1 on price and Claude Sonnet 4.6 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.2Capabilities Index (ECI): GPT-5.2 153.5 · Claude Sonnet 4.6 152.3 · GLM-5.1 149.9
  • Lowest priceGLM-5.1GLM-5.1 $2.15 · GPT-5.2 $4.81 · Claude Sonnet 4.6 $6.00 per 1M tokens (3:1 blend)
  • Longest contextClaude Sonnet 4.6Claude Sonnet 4.6 1,000,000 · GPT-5.2 400,000 · GLM-5.1 200,000 tokens
  • Widest inputsClaude Sonnet 4.6Claude Sonnet 4.6: Text, Images, PDFs · GLM-5.1: Text · GPT-5.2: Text, Images
  • Self-hostingGLM-5.1Publishes downloadable weights
How the score is built
MeasureWeightClaude Sonnet 4.6GLM-5.1GPT-5.2
CapabilityCapabilities Index (ECI)50%817883
Price25%133418
Inputs & features15%804570
Context window10%603244
Overall100%62/10057/10061/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Claude Sonnet 4.6 vs GLM-5.1 vs GPT-5.2 specifications side by side
SpecificationClaude Sonnet 4.6AnthropicGLM-5.1Z.ai (Zhipu)GPT-5.2OpenAI
Capability
Capabilities Index (ECI)152.3149.9153.5 (best)
ECI rank#40 of 148#51 of 148#38 of 148 (best)
GPQA DiamondGraduate-level science questions87.4%89.9%91.4% (best)
FrontierMath Tiers 1–3Research-level mathematics—36.8%67.4% (best)
OTIS Mock AIME 2024–2025Competition mathematics85.8%93.3%96.1% (best)
SWE-bench VerifiedFixing real GitHub issues75.2% (best)74.2%73.8%
SimpleQA VerifiedShort factual questions35.5%34.0%37.1% (best)
Price per million tokens
Input$3.00$1.40 (best)$1.75
Output$15.00$4.40 (best)$14.00
Cached input$0.30$0.26$0.175 (best)
Blended (3:1)$6.00$2.15 (best)$4.81
Long-context rateSame rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Z.AI APIOfficial OpenAI API
Limits
Context window1,000,000 tokens (best)200,000 tokens400,000 tokens
Max output64,000 tokens131,072 tokens (best)128,000 tokens
Inputs and features
TextYesYesYes
ImagesYesNoYes
PDFsYesNoNo
AudioNoNoNo
VideoNoNoNo
ReasoningYeslow · medium · high · maxYesYeslow · medium · high · xhigh
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryOpenProprietary
API model IDclaude-sonnet-4-6glm-5.1gpt-5.2
API providers41 (best)4021
ReleasedFeb 17, 2026Apr 7, 2026Dec 11, 2025
Knowledge cutoffAug 31, 2025—Aug 31, 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Claude Sonnet 4.6$60.00
  • GLM-5.1$22.80
  • GPT-5.2$45.50
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 4.6, GLM-5.1 or GPT-5.2?

It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, GLM-5.1 57/100), so choose by what matters most for your work: GPT-5.2 for raw capability, GLM-5.1 on price and Claude Sonnet 4.6 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 4.6, GLM-5.1 or GPT-5.2?

GLM-5.1 is cheaper at $1.40 input / $4.40 output per million tokens (official Z.AI API price). GPT-5.2 costs $1.75 input / $14.00 output per million tokens (official OpenAI API price); Claude Sonnet 4.6 costs $3.00 input / $15.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $2.15 per million tokens for GLM-5.1 versus $4.81 for GPT-5.2 (2.2× as much) and $6.00 for Claude Sonnet 4.6 (2.8× as much).

Which scores higher on benchmarks?

GPT-5.2 scores higher on the Capabilities Index (ECI): GPT-5.2 153.5 (#38 of 148), Claude Sonnet 4.6 152.3 (#40 of 148) and GLM-5.1 149.9 (#51 of 148). The confidence ranges of the top two overlap (151.7–155.4 vs 149.6–154.7), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.2 91.4%, GLM-5.1 89.9%, Claude Sonnet 4.6 87.4%; OTIS Mock AIME 2024–2025 — GPT-5.2 96.1%, GLM-5.1 93.3%, Claude Sonnet 4.6 85.8%; SWE-bench Verified — Claude Sonnet 4.6 75.2%, GLM-5.1 74.2%, GPT-5.2 73.8%; SimpleQA Verified — GPT-5.2 37.1%, Claude Sonnet 4.6 35.5%, GLM-5.1 34.0%.

Which is better for coding?

Claude Sonnet 4.6 resolves more real GitHub issues on SWE-bench Verified: Claude Sonnet 4.6 75.2%, GLM-5.1 74.2% and GPT-5.2 73.8%. All three support tool calling for agent workflows.

Which has the bigger context window?

Claude Sonnet 4.6 has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5.2 and 200,000 for GLM-5.1. Maximum output per response: Claude Sonnet 4.6 up to 64,000, GLM-5.1 up to 131,072, GPT-5.2 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 4.6 accepts text, images and PDFs; GLM-5.1 accepts text; GPT-5.2 accepts text and images. Claude Sonnet 4.6 handles the widest range of inputs.

Are any of these open source?

GLM-5.1 publishes its weights and can be self-hosted; Claude Sonnet 4.6 and GPT-5.2 is proprietary.

Which is newer?

GLM-5.1 is the newest, released Apr 7, 2026. Claude Sonnet 4.6 came out Feb 17, 2026; GPT-5.2 came out Dec 11, 2025. Knowledge cutoff: Claude Sonnet 4.6 Aug 31, 2025, GPT-5.2 Aug 31, 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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