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Comparison · 3 models · Updated Oct 4, 2026

Claude Opus 4.1 vs Claude Haiku 4.5 vs o3-pro

Claude Haiku 4.5 comes out ahead, 58 to 51 and 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
  2. Our pick

    Anthropic

    Claude Haiku 4.5

    Released Oct 15, 2025

    58/100
    • ECI142.4
    • Price$1.00 / $5.00
    • Context200K
  3. OpenAI

    o3-pro

    Released Jun 10, 2025

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

Claude Haiku 4.5 is our pick

Claude Haiku 4.5 is the better all-round choice, scoring 58/100 against o3-pro (51) and Claude Opus 4.1 (49). It leads on price and inputs & features. o3-pro wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • Capabilityo3-proCapabilities Index (ECI): o3-pro 147.4 · Claude Opus 4.1 144.1 · Claude Haiku 4.5 142.4
  • Lowest priceClaude Haiku 4.5Claude Haiku 4.5 $2.00 · Claude Opus 4.1 $30.00 · o3-pro $35.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameClaude Opus 4.1 200,000 · Claude Haiku 4.5 200,000 · o3-pro 200,000 tokens
  • Widest inputsClaude Opus 4.1 and Claude Haiku 4.5Claude Opus 4.1: Text, Images, PDFs · Claude Haiku 4.5: Text, Images, PDFs · o3-pro: Text, Images
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightClaude Opus 4.1Claude Haiku 4.5o3-pro
CapabilityCapabilities Index (ECI)50%716975
Price25%0360
Inputs & features15%708070
Context window10%323232
Overall100%49/10058/10051/100
02 — Side by side

Every spec in one table

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

Claude Opus 4.1 vs Claude Haiku 4.5 vs o3-pro specifications side by side
SpecificationClaude Opus 4.1AnthropicClaude Haiku 4.5Anthropico3-proOpenAI
Capability
Capabilities Index (ECI)144.1142.4147.4 (best)
ECI rank#81 of 148#90 of 148#60 of 148 (best)
GPQA DiamondGraduate-level science questions77.3% (best)71.2%—
FrontierMath Tiers 1–3Research-level mathematics12.6%——
OTIS Mock AIME 2024–2025Competition mathematics68.9% (best)66.7%—
SWE-bench VerifiedFixing real GitHub issues73.4%——
SimpleQA VerifiedShort factual questions—13.2%—
Price per million tokens
Input$15.00$1.00 (best)$20.00
Output$75.00$5.00 (best)$80.00
Cached input—$0.10—
Blended (3:1)$30.00$2.00 (best)$35.00
Long-context rateSame rateSame rateSame rate
Price sourceMedian of 14 providersOfficial Anthropic APIOfficial OpenAI API
Limits
Context window200,000 tokens200,000 tokens200,000 tokens
Max output32,000 tokens64,000 tokens100,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesNo
AudioNoNoNo
VideoNoNoNo
ReasoningYesYesYeslow · medium · high
Tool callingYesYesYes
Structured outputNoYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model ID—claude-haiku-4-5o3-pro
API providers1434 (best)6
ReleasedAug 5, 2025Oct 15, 2025Jun 10, 2025
Knowledge cutoffMar 31, 2025Feb 28, 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
  • Claude Haiku 4.5$20.00
  • o3-pro$360.00
04 — Questions

Which should you choose?

Which is better: Claude Opus 4.1, Claude Haiku 4.5 or o3-pro?

Claude Haiku 4.5 is the better all-round choice, scoring 58/100 against o3-pro (51) and Claude Opus 4.1 (49). It leads on price and inputs & features. o3-pro wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Opus 4.1, Claude Haiku 4.5 or o3-pro?

Claude Haiku 4.5 is cheaper at $1.00 input / $5.00 output per million tokens (official Anthropic API price). Claude Opus 4.1 costs $15.00 input / $75.00 output per million tokens (median across 14 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 $2.00 per million tokens for Claude Haiku 4.5 versus $30.00 for Claude Opus 4.1 (15× as much) and $35.00 for o3-pro (18× as much).

Which scores higher on benchmarks?

o3-pro scores higher on the Capabilities Index (ECI): o3-pro 147.4 (#60 of 148), Claude Opus 4.1 144.1 (#81 of 148) and Claude Haiku 4.5 142.4 (#90 of 148). The confidence ranges of the top two overlap (145.8–149.7 vs 141.6–146.0), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Haiku 4.5 and 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 4.1, Claude Haiku 4.5 and o3-pro share the same 200,000-token context window. Maximum output per response: Claude Opus 4.1 up to 32,000, Claude Haiku 4.5 up to 64,000, o3-pro up to 100,000 tokens.

Which can read images, PDFs, audio or video?

Claude Opus 4.1 accepts text, images and PDFs; Claude Haiku 4.5 accepts text, images and PDFs; o3-pro accepts text and images. Claude Opus 4.1 handles the widest range of inputs.

Are any of these open source?

No. Claude Opus 4.1, Claude Haiku 4.5 and o3-pro are proprietary and only available through APIs and apps.

Which is newer?

Claude Haiku 4.5 is the newest, released Oct 15, 2025. Claude Opus 4.1 came out Aug 5, 2025; o3-pro came out Jun 10, 2025. Knowledge cutoff: Claude Opus 4.1 Mar 31, 2025, Claude Haiku 4.5 Feb 28, 2025, 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.