Claude Haiku 4.5 vs GPT-5.5
2026 - Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.5 is open-weights - free to self-host with no API costs. Claude Haiku 4.5 requires paid API access.
- •Claude Haiku 4.5 has a 200K context window - 2x larger than GPT-5.5's 128K. Better for long documents and large codebases.
Specs comparison
| Claude Haiku 4.5 | GPT-5.5 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓200K | 128K |
| Input / 1M tokens | $0.80 | ✓Free (self-host) |
| Output / 1M tokens | $4.00 | Free (self-host) |
| Release date | 2025-10 | 2026-04 |
Benchmarks
| Benchmark | Claude Haiku 4.5 | GPT-5.5 |
|---|---|---|
| MMLU | ~82% | - |
| HumanEval | ~88% | - |
Scores sourced from official provider release posts.
Strengths
Claude Haiku 4.5
- ✓Lowest latency in the Claude lineup
- ✓Extremely cost-effective at scale
- ✓Strong at classification and extraction
- ✓Good at following structured output schemas
- ✓Handles 200K context at low cost
GPT-5.5
- ✓Improved instruction following over GPT-4o
- ✓Stronger long-context coherence
- ✓Better output consistency for agentic pipelines
- ✓GPT-5.5 Pro tier for reliability-critical workloads
- ✓Easier migration path than jumping from GPT-4o to GPT-5
Which should you choose?
Choose Claude Haiku 4.5 if you need...
- →High-volume API pipelines
- →Real-time classification
- →Form and document extraction
- →Low-latency chatbots
Choose GPT-5.5 if you need...
- →Production API integrations migrating from GPT-4o
- →Agentic workflows needing consistent structured output
- →Long-context document tasks
- →Teams deferring full GPT-5 migration costs