ZMIME
Comparison · 3 models · Updated Oct 4, 2026

Claude Sonnet 4.6 vs Claude Sonnet 4.5 vs GPT-5.2

Too close to call on our weighted score (Claude Sonnet 4.6 62, GPT-5.2 61, Claude Sonnet 4.5 55). 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. Anthropic

    Claude Sonnet 4.5

    Released Sep 29, 2025

    55/100
    • ECI146.8
    • Price$3.00 / $15.00
    • Context200K
    Full specs Remove Claude Sonnet 4.5

  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, Claude Sonnet 4.5 55/100), so choose by what matters most for your work: GPT-5.2 for raw capability 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 · Claude Sonnet 4.5 146.8
  • Lowest priceGPT-5.2GPT-5.2 $4.81 · Claude Sonnet 4.6 $6.00 · Claude Sonnet 4.5 $6.00 per 1M tokens (3:1 blend)
  • Longest contextClaude Sonnet 4.6Claude Sonnet 4.6 1,000,000 · GPT-5.2 400,000 · Claude Sonnet 4.5 200,000 tokens
  • Widest inputsClaude Sonnet 4.6 and Claude Sonnet 4.5Claude Sonnet 4.6: Text, Images, PDFs · Claude Sonnet 4.5: Text, Images, PDFs · GPT-5.2: Text, Images
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightClaude Sonnet 4.6Claude Sonnet 4.5GPT-5.2
CapabilityCapabilities Index (ECI)50%817483
Price25%131318
Inputs & features15%808070
Context window10%603244
Overall100%62/10055/10061/100
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 Claude Sonnet 4.5 vs GPT-5.2 specifications side by side
SpecificationClaude Sonnet 4.6AnthropicClaude Sonnet 4.5AnthropicGPT-5.2OpenAI
Capability
Capabilities Index (ECI)152.3146.8153.5 (best)
ECI rank#40 of 148#64 of 148#38 of 148 (best)
GPQA DiamondGraduate-level science questions87.4%82.3%91.4% (best)
FrontierMath Tiers 1–3Research-level mathematics—23.9%67.4% (best)
OTIS Mock AIME 2024–2025Competition mathematics85.8%77.8%96.1% (best)
SWE-bench VerifiedFixing real GitHub issues75.2% (best)71.3%73.8%
SimpleQA VerifiedShort factual questions35.5%30.7%37.1% (best)
Price per million tokens
Input$3.00$3.00$1.75 (best)
Output$15.00$15.00$14.00 (best)
Cached input$0.30$0.30$0.175 (best)
Blended (3:1)$6.00$6.00$4.81 (best)
Long-context rateSame rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Anthropic APIOfficial OpenAI API
Limits
Context window1,000,000 tokens (best)200,000 tokens400,000 tokens
Max output64,000 tokens64,000 tokens128,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesNo
AudioNoNoNo
VideoNoNoNo
ReasoningYeslow · medium · high · maxYesYeslow · medium · high · xhigh
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDclaude-sonnet-4-6claude-sonnet-4-5gpt-5.2
API providers41 (best)2821
ReleasedFeb 17, 2026Sep 29, 2025Dec 11, 2025
Knowledge cutoffAug 31, 2025Jul 31, 2025Aug 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
  • Claude Sonnet 4.5$60.00
  • GPT-5.2$45.50
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 4.6, Claude Sonnet 4.5 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, Claude Sonnet 4.5 55/100), so choose by what matters most for your work: GPT-5.2 for raw capability 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, Claude Sonnet 4.5 or GPT-5.2?

GPT-5.2 is cheaper at $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); Claude Sonnet 4.5 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 $4.81 per million tokens for GPT-5.2 versus $6.00 for Claude Sonnet 4.6 (1.2× as much) and $6.00 for Claude Sonnet 4.5 (1.2× 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 Claude Sonnet 4.5 146.8 (#64 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%, Claude Sonnet 4.6 87.4%, Claude Sonnet 4.5 82.3%; OTIS Mock AIME 2024–2025 — GPT-5.2 96.1%, Claude Sonnet 4.6 85.8%, Claude Sonnet 4.5 77.8%; SWE-bench Verified — Claude Sonnet 4.6 75.2%, GPT-5.2 73.8%, Claude Sonnet 4.5 71.3%; SimpleQA Verified — GPT-5.2 37.1%, Claude Sonnet 4.6 35.5%, Claude Sonnet 4.5 30.7%.

Which is better for coding?

Claude Sonnet 4.6 resolves more real GitHub issues on SWE-bench Verified: Claude Sonnet 4.6 75.2%, GPT-5.2 73.8% and Claude Sonnet 4.5 71.3%. 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 Claude Sonnet 4.5. Maximum output per response: Claude Sonnet 4.6 up to 64,000, Claude Sonnet 4.5 up to 64,000, 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; Claude Sonnet 4.5 accepts text, images and PDFs; GPT-5.2 accepts text and images. Claude Sonnet 4.6 handles the widest range of inputs.

Are any of these open source?

No. Claude Sonnet 4.6, Claude Sonnet 4.5 and GPT-5.2 are proprietary and only available through APIs and apps.

Which is newer?

Claude Sonnet 4.6 is the newest, released Feb 17, 2026. GPT-5.2 came out Dec 11, 2025; Claude Sonnet 4.5 came out Sep 29, 2025. Knowledge cutoff: Claude Sonnet 4.6 Aug 31, 2025, Claude Sonnet 4.5 Jul 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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