LLM Reference

Claude Haiku 4.5 vs o3

Claude Haiku 4.5 (2025) and o3 (2025) are frontier reasoning models from Anthropic and OpenAI. Claude Haiku 4.5 ships a 200k-token context window, while o3 ships a 200k-token context window. On SWE-bench Verified, Claude Haiku 4.5 leads by 1.6 pts. On pricing, Claude Haiku 4.5 costs $0.80/1M input tokens versus $2/1M 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.

Claude Haiku 4.5 is ~150% cheaper at $0.80/1M; pay for o3 only for coding workflow support.

Decision scorecard

Local evidence first
SignalClaude Haiku 4.5o3
Best formultimodal apps, tool-calling agents, and provider-routed productionreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window200k200k
Cheapest output$4/1M tokens$8/1M tokens
Provider routes8 tracked3 tracked
Shared benchmarksSWE-bench Verified leader1 rows

Decision tradeoffs

Choose Claude Haiku 4.5 when...
  • Claude Haiku 4.5 holds a shared-benchmark lead on SWE-bench Verified, ahead by 1.6 points.
  • Claude Haiku 4.5 has the lower cheapest tracked output price at $4/1M tokens.
  • Claude Haiku 4.5 has broader tracked provider coverage for fallback and procurement flexibility.
  • Local decision data tags Claude Haiku 4.5 for Coding, RAG, and Agents.
Choose o3 when...
  • o3 uniquely exposes Reasoning in local model data.
  • Local decision data tags o3 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.

Lower estimate Claude Haiku 4.5

Claude Haiku 4.5

$1,640

Cheapest tracked route/tier: AWS Bedrock

o3

$3,600

Cheapest tracked route/tier: OpenAI API

Estimated monthly gap: $1,960. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Haiku 4.5 -> o3
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • o3 is $4/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • o3 adds Reasoning in local capability data.
o3 -> Claude Haiku 4.5
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • Claude Haiku 4.5 is $4/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Reasoning before moving production traffic.

Specs

Specification
Released2025-10-012025-04-16
Context window200k200k
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff2025-022024-06

Pricing and availability

Pricing attributeClaude Haiku 4.5o3
Input price$0.80/1M tokens$2/1M tokens
Output price$4/1M tokens$8/1M tokens
Providers

Capabilities

CapabilityClaude Haiku 4.5o3
VisionYesYes
MultimodalYesYes
ReasoningNoYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Haiku 4.5o3
SWE-bench Verified73.371.7

Deep dive

On shared benchmark coverage, SWE-bench Verified has Claude Haiku 4.5 at 73.3 and o3 at 71.7, with Claude Haiku 4.5 ahead by 1.6 points. The largest visible gap is 1.6 points on SWE-bench Verified, 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 reasoning mode: o3. Both models share vision, multimodal input, function calling, and tool use, 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 Haiku 4.5 lists $0.80/1M input and $4/1M output tokens on the cheapest tracked provider, while o3 lists $2/1M input and $8/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Claude Haiku 4.5 lower by about $2.04 per million blended tokens. Availability is 8 providers versus 3, so concentration risk also matters.

Choose Claude Haiku 4.5 when coding workflow support, lower input-token cost, and broader provider choice are central to the workload. Choose o3 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 Haiku 4.5 or o3?

Claude Haiku 4.5 supports 200k tokens, while o3 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 Haiku 4.5 or o3?

Claude Haiku 4.5 is cheaper on tracked token pricing. Claude Haiku 4.5 costs $0.80/1M input and $4/1M output tokens. o3 costs $2/1M input and $8/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Haiku 4.5 or o3 open source?

Claude Haiku 4.5 is listed under Proprietary. o3 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 Haiku 4.5 or o3?

Both Claude Haiku 4.5 and o3 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, Claude Haiku 4.5 or o3?

Both Claude Haiku 4.5 and o3 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Where can I run Claude Haiku 4.5 and o3?

Claude Haiku 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, AWS Bedrock, and GCP Vertex AI. o3 is available on OpenAI API, OpenRouter, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-06-08. Data sourced from public model cards and provider documentation.