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Comparison · 3 models · Updated Oct 4, 2026

Claude Opus 4 vs o3 vs o3-pro

o3 comes out ahead, 58 to 51 and 48 on our weighted score, and it is the cheaper option too.

  1. Anthropic

    Claude Opus 4

    Released May 22, 2025

    48/100
    • ECI142.7
    • Price$15.00 / $75.00
    • Context200K
  2. Our pick

    OpenAI

    o3

    Released Apr 16, 2025

    58/100
    • ECI146.9
    • Price$2.00 / $8.00
    • Context200K
  3. OpenAI

    o3-pro

    Released Jun 10, 2025

    51/100
    • ECI147.4
    • Price$20.00 / $80.00
    • Context200K
01 — Verdict

o3 is our pick

o3 is the better all-round choice, scoring 58/100 against o3-pro (51) and Claude Opus 4 (48). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • Capabilityo3-proCapabilities Index (ECI): o3-pro 147.4 · o3 146.9 · Claude Opus 4 142.7
  • Lowest priceo3o3 $3.50 · Claude Opus 4 $30.00 · o3-pro $35.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameClaude Opus 4 200,000 · o3 200,000 · o3-pro 200,000 tokens
  • Widest inputsClaude Opus 4 and o3Claude Opus 4: Text, Images, PDFs · o3: Text, Images, PDFs · o3-pro: Text, Images
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightClaude Opus 4o3o3-pro
CapabilityCapabilities Index (ECI)50%697475
Price25%0240
Inputs & features15%708070
Context window10%323232
Overall100%48/10058/10051/100
02 — Side by side

Every spec in one table

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

Claude Opus 4 vs o3 vs o3-pro specifications side by side
SpecificationClaude Opus 4Anthropico3OpenAIo3-proOpenAI
Capability
Capabilities Index (ECI)142.7146.9147.4 (best)
ECI rank#87 of 148#63 of 148#60 of 148 (best)
GPQA DiamondGraduate-level science questions76.3%81.8% (best)—
FrontierMath Tiers 1–3Research-level mathematics—33.3%—
OTIS Mock AIME 2024–2025Competition mathematics64.4%84.4% (best)—
SWE-bench VerifiedFixing real GitHub issues70.7% (best)62.3%—
SimpleQA VerifiedShort factual questions—49.4%—
Price per million tokens
Input$15.00$2.00 (best)$20.00
Output$75.00$8.00 (best)$80.00
Cached input—$0.50—
Blended (3:1)$30.00$3.50 (best)$35.00
Long-context rateSame rateSame rateSame rate
Price sourceMedian of 5 providersOfficial OpenAI APIOfficial OpenAI API
Limits
Context window200,000 tokens200,000 tokens200,000 tokens
Max output32,000 tokens100,000 tokens (best)100,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesNo
AudioNoNoNo
VideoNoNoNo
ReasoningYesYeslow · medium · highYeslow · medium · high
Tool callingYesYesYes
Structured outputNoYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model ID—o3o3-pro
API providers518 (best)6
ReleasedMay 22, 2025Apr 16, 2025Jun 10, 2025
Knowledge cutoffMar 31, 2025May 2024May 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$300.00
  • o3$36.00
  • o3-pro$360.00
04 — Questions

Which should you choose?

Which is better: Claude Opus 4, o3 or o3-pro?

o3 is the better all-round choice, scoring 58/100 against o3-pro (51) and Claude Opus 4 (48). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Opus 4, o3 or o3-pro?

o3 is cheaper at $2.00 input / $8.00 output per million tokens (official OpenAI API price). Claude Opus 4 costs $15.00 input / $75.00 output per million tokens (median across 5 API providers); o3-pro costs $20.00 input / $80.00 output per million tokens (official OpenAI API price). 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 (8.6× as much) and $35.00 for o3-pro (10× as much).

Which scores higher on benchmarks?

o3-pro scores higher on the Capabilities Index (ECI): o3-pro 147.4 (#60 of 148), o3 146.9 (#63 of 148) and Claude Opus 4 142.7 (#87 of 148). The confidence ranges of the top two overlap (145.8–149.7 vs 144.9–148.6), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for o3-pro yet, so there is no like-for-like coding score. On overall capability, o3-pro leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Claude Opus 4, o3 and o3-pro share the same 200,000-token context window. Maximum output per response: Claude Opus 4 up to 32,000, o3 up to 100,000, o3-pro up to 100,000 tokens.

Which can read images, PDFs, audio or video?

Claude Opus 4 accepts text, images and PDFs; o3 accepts text, images and PDFs; o3-pro accepts text and images. Claude Opus 4 handles the widest range of inputs.

Are any of these open source?

No. Claude Opus 4, o3 and o3-pro are proprietary and only available through APIs and apps.

Which is newer?

o3-pro is the newest, released Jun 10, 2025. Claude Opus 4 came out May 22, 2025; o3 came out Apr 16, 2025. Knowledge cutoff: Claude Opus 4 Mar 31, 2025, o3 May 2024, o3-pro 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.