o3 vs Claude Haiku 4.5
Too close to call on our weighted score (Claude Haiku 4.5 58, o3 58). The right pick depends on what you value most.
OpenAIo3
58/100- ECI146.9
- Price$2.00 / $8.00
- Context200K
AnthropicClaude Haiku 4.5
58/100- ECI142.4
- Price$1.00 / $5.00
- Context200K
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within a point (Claude Haiku 4.5 58/100, o3 58/100), so choose by what matters most for your work: o3 for raw capability and Claude Haiku 4.5 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- Capabilityo3Capabilities Index (ECI): o3 146.9 · Claude Haiku 4.5 142.4
- Lowest priceClaude Haiku 4.5Claude Haiku 4.5 $2.00 · o3 $3.50 per 1M tokens (3:1 blend)
- Longest contextAbout the sameo3 200,000 · Claude Haiku 4.5 200,000 tokens
- Widest inputsSame inputso3: Text, Images, PDFs · Claude Haiku 4.5: Text, Images, PDFs
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | o3 | Claude Haiku 4.5 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 74 | 69 |
| Price | 25% | 24 | 36 |
| Inputs & features | 15% | 80 | 80 |
| Context window | 10% | 32 | 32 |
| Overall | 100% | 58/100 | 58/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | o3OpenAI | Claude Haiku 4.5Anthropic |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 146.9 (best) | 142.4 |
| ECI rank | #63 of 148 (best) | #90 of 148 |
| GPQA DiamondGraduate-level science questions | 81.8% (best) | 71.2% |
| FrontierMath Tiers 1–3Research-level mathematics | 33.3% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 84.4% (best) | 66.7% |
| SWE-bench VerifiedFixing real GitHub issues | 62.3% | — |
| SimpleQA VerifiedShort factual questions | 49.4% (best) | 13.2% |
| Price per million tokens | ||
| Input | $2.00 | $1.00 (best) |
| Output | $8.00 | $5.00 (best) |
| Cached input | $0.50 | $0.10 (best) |
| Blended (3:1) | $3.50 | $2.00 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official Anthropic API |
| Limits | ||
| Context window | 200,000 tokens | 200,000 tokens |
| Max output | 100,000 tokens (best) | 64,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | Yes | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | o3 | claude-haiku-4-5 |
| API providers | 18 | 34 (best) |
| Released | Apr 16, 2025 | Oct 15, 2025 |
| Knowledge cutoff | May 2024 | Feb 28, 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- o3$36.00
- Claude Haiku 4.5$20.00
Which should you choose?
Which is better: o3 or Claude Haiku 4.5?
It is close. Our weighted score puts them within a point (Claude Haiku 4.5 58/100, o3 58/100), so choose by what matters most for your work: o3 for raw capability and Claude Haiku 4.5 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, o3 or Claude Haiku 4.5?
Claude Haiku 4.5 is cheaper at $1.00 input / $5.00 output per million tokens (official Anthropic API price). o3 costs $2.00 input / $8.00 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 $3.50 for o3 (1.8× as much).
Which scores higher on benchmarks?
o3 scores higher on the Capabilities Index (ECI): o3 146.9 (#63 of 148) and Claude Haiku 4.5 142.4 (#90 of 148). Their confidence ranges do not overlap (144.9–148.6 vs 139.5–144.3), so the gap is a real one. On individual benchmarks: GPQA Diamond — o3 81.8%, Claude Haiku 4.5 71.2%; OTIS Mock AIME 2024–2025 — o3 84.4%, Claude Haiku 4.5 66.7%; SimpleQA Verified — o3 49.4%, Claude Haiku 4.5 13.2%.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Haiku 4.5 yet, so there is no like-for-like coding score. On overall capability, o3 leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
o3 and Claude Haiku 4.5 share the same 200,000-token context window. Maximum output per response: o3 up to 100,000, Claude Haiku 4.5 up to 64,000 tokens.
Which can read images, PDFs, audio or video?
o3 accepts text, images and PDFs; Claude Haiku 4.5 accepts text, images and PDFs. They handle the same number of input types.
Are any of these open source?
No. o3 and Claude Haiku 4.5 are proprietary and only available through APIs and apps.
Which is newer?
Claude Haiku 4.5 is the newest, released Oct 15, 2025. o3 came out Apr 16, 2025. Knowledge cutoff: o3 May 2024, Claude Haiku 4.5 Feb 28, 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.
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