Claude 3.5 Haiku vs o3 Mini
Claude 3.5 Haiku (2024) and o3 Mini (2025) are frontier-tier reasoning models from Anthropic and OpenAI. Both ship a 200K-token context window. On LMArena Text Arena - Creative Writing, o3 Mini leads by 41 pts. On pricing, Claude 3.5 Haiku costs $0.80/1M input tokens versus $1.10/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
o3 Mini is safer overall; choose Claude 3.5 Haiku when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | Claude 3.5 Haiku | o3 Mini |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and provider-routed production | reasoning-heavy apps, tool-calling agents, and provider-routed production |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200K | 200K |
| Cheapest output | $4/1M tokens | $4.40/1M tokens |
| Provider routes | 6 tracked | 4 tracked |
| Shared benchmarks | 1 shared | LMArena Text Arena - Creative Writing leader |
Decision tradeoffs
- Claude 3.5 Haiku has the lower cheapest tracked output price at $4/1M tokens.
- Claude 3.5 Haiku has broader tracked provider coverage for fallback and route flexibility.
- Claude 3.5 Haiku uniquely exposes Vision in local model data.
- Local decision data tags Claude 3.5 Haiku for Coding, RAG, and Agents.
- o3 Mini holds a shared-benchmark lead on LMArena Text Arena - Creative Writing, ahead by 41 points.
- o3 Mini uniquely exposes JSON / Tool use in local model data.
- Local decision data tags o3 Mini for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude 3.5 Haiku
$1,640
Cheapest tracked route/tier: Anthropic
o3 Mini
$1,980
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $340. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- o3 Mini is $0.40/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision before moving production traffic.
- o3 Mini adds JSON / Tool use in local capability data.
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- Claude 3.5 Haiku is $0.40/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for JSON / Tool use before moving production traffic.
- Claude 3.5 Haiku adds Vision in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-10-22 | 2025-01-31 |
| Context window | 200K | 200K |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Restricted | Restricted |
| Knowledge cutoff | - | 2025-04 |
Pricing and availability
| Pricing attribute | Claude 3.5 Haiku | o3 Mini |
|---|---|---|
| Input price | $0.80/1M tokens | $1.10/1M tokens |
| Output price | $4/1M tokens | $4.40/1M tokens |
| Providers |
Capabilities
| Capability | Claude 3.5 Haiku | o3 Mini |
|---|---|---|
| Vision | Yes | No |
| Multimodal | No | No |
| Reasoning | Yes | Yes |
| JSON / Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude 3.5 Haiku | o3 Mini |
|---|---|---|
| LMArena Text Arena - Creative Writing | 1232.0 | 1273.0 |
Deep dive
On shared benchmark coverage, LMArena Text Arena - Creative Writing has Claude 3.5 Haiku at 1232 and o3 Mini at 1273, with o3 Mini ahead by 41 points. The largest visible gap is 41 points on LMArena Text Arena - Creative Writing, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Claude 3.5 Haiku, JSON / Tool use: o3 Mini, and JSON / Tool use: o3 Mini. Both models share reasoning mode, structured outputs, and code execution, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Claude 3.5 Haiku lists $0.80/1M input and $4/1M output tokens on the cheapest listed provider, while o3 Mini lists $1.10/1M input and $4.40/1M output tokens on the cheapest listed provider. A 70/30 input-output blend puts Claude 3.5 Haiku lower by about $0.33 per million blended tokens. Availability is 6 providers versus 4, so concentration risk also matters.
Choose Claude 3.5 Haiku when coding workflow support, lower input-token cost, and broader provider choice are central to the workload. Choose o3 Mini when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Claude 3.5 Haiku or o3 Mini?
Claude 3.5 Haiku supports 200K tokens, while o3 Mini supports 200K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude 3.5 Haiku or o3 Mini?
Claude 3.5 Haiku is cheaper on listed token pricing. Claude 3.5 Haiku costs $0.80/1M input and $4/1M output tokens. o3 Mini costs $1.10/1M input and $4.40/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude 3.5 Haiku or o3 Mini open source?
Claude 3.5 Haiku is listed under Proprietary. o3 Mini is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude 3.5 Haiku or o3 Mini?
Claude 3.5 Haiku has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, Claude 3.5 Haiku or o3 Mini?
Both Claude 3.5 Haiku and o3 Mini expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude 3.5 Haiku and o3 Mini?
Claude 3.5 Haiku is available on Anthropic, OpenRouter, AWS Bedrock, GCP Vertex AI, and Replicate API. o3 Mini is available on OpenRouter, Azure OpenAI, OpenAI API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-10-17. Data sourced from public model cards and provider documentation.