ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Claude Opus 4.1 vs o3

o3 comes out ahead, 58 to 49 on our weighted score, and it is the cheaper option too.

  1. Anthropic

    Claude Opus 4.1

    Released Aug 5, 2025

    49/100
    • ECI144.1
    • Price$15.00 / $75.00
    • Context200K
    Full specs Remove Claude Opus 4.1
  2. Our pick

    OpenAI

    o3

    Released Apr 16, 2025

    58/100
    • ECI146.9
    • Price$2.00 / $8.00
    • Context200K
    Full specs Remove o3

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

o3 is our pick

o3 is the better all-round choice, scoring 58/100 against Claude Opus 4.1 (49). It leads on capability, price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • Capabilityo3Capabilities Index (ECI): o3 146.9 · Claude Opus 4.1 144.1
  • Lowest priceo3o3 $3.50 · Claude Opus 4.1 $30.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameClaude Opus 4.1 200,000 · o3 200,000 tokens
  • Widest inputsSame inputsClaude Opus 4.1: Text, Images, PDFs · o3: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Opus 4.1o3
CapabilityCapabilities Index (ECI)50%7174
Price25%024
Inputs & features15%7080
Context window10%3232
Overall100%49/10058/100
02 — Side by side

Every spec in one table

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

Claude Opus 4.1 vs o3 specifications side by side
SpecificationClaude Opus 4.1Anthropico3OpenAI
Capability
Capabilities Index (ECI)144.1146.9 (best)
ECI rank#81 of 148#63 of 148 (best)
GPQA DiamondGraduate-level science questions77.3%81.8% (best)
FrontierMath Tiers 1–3Research-level mathematics12.6%33.3% (best)
OTIS Mock AIME 2024–2025Competition mathematics68.9%84.4% (best)
SWE-bench VerifiedFixing real GitHub issues73.4% (best)62.3%
SimpleQA VerifiedShort factual questions—49.4%
Price per million tokens
Input$15.00$2.00 (best)
Output$75.00$8.00 (best)
Cached input—$0.50
Blended (3:1)$30.00$3.50 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 14 providersOfficial OpenAI API
Limits
Context window200,000 tokens200,000 tokens
Max output32,000 tokens100,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioNoNo
VideoNoNo
ReasoningYesYeslow · medium · high
Tool callingYesYes
Structured outputNoYes
Availability
WeightsProprietaryProprietary
API model ID—o3
API providers1418 (best)
ReleasedAug 5, 2025Apr 16, 2025
Knowledge cutoffMar 31, 2025May 2024
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 Opus 4.1$300.00
  • o3$36.00
04 — Questions

Which should you choose?

Which is better: Claude Opus 4.1 or o3?

o3 is the better all-round choice, scoring 58/100 against Claude Opus 4.1 (49). It leads on capability, price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Opus 4.1 or o3?

o3 is cheaper at $2.00 input / $8.00 output per million tokens (official OpenAI API price). Claude Opus 4.1 costs $15.00 input / $75.00 output per million tokens (median across 14 API providers). At a typical mix of three input tokens to one output token, that is $3.50 per million tokens for o3 versus $30.00 for Claude Opus 4.1 (8.6× as much).

Which scores higher on benchmarks?

o3 scores higher on the Capabilities Index (ECI): o3 146.9 (#63 of 148) and Claude Opus 4.1 144.1 (#81 of 148). The confidence ranges of the top two overlap (144.9–148.6 vs 141.6–146.0), so treat the gap as small. On individual benchmarks: GPQA Diamond — o3 81.8%, Claude Opus 4.1 77.3%; FrontierMath Tiers 1–3 — o3 33.3%, Claude Opus 4.1 12.6%; OTIS Mock AIME 2024–2025 — o3 84.4%, Claude Opus 4.1 68.9%; SWE-bench Verified — Claude Opus 4.1 73.4%, o3 62.3%.

Which is better for coding?

Claude Opus 4.1 resolves more real GitHub issues on SWE-bench Verified: Claude Opus 4.1 73.4% and o3 62.3%. Both support tool calling for agent workflows.

Which has the bigger context window?

Claude Opus 4.1 and o3 share the same 200,000-token context window. Maximum output per response: Claude Opus 4.1 up to 32,000, o3 up to 100,000 tokens.

Which can read images, PDFs, audio or video?

Claude Opus 4.1 accepts text, images and PDFs; o3 accepts text, images and PDFs. They handle the same number of input types.

Are any of these open source?

No. Claude Opus 4.1 and o3 are proprietary and only available through APIs and apps.

Which is newer?

Claude Opus 4.1 is the newest, released Aug 5, 2025. o3 came out Apr 16, 2025. Knowledge cutoff: Claude Opus 4.1 Mar 31, 2025, o3 May 2024.

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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