Claude Opus 4.8 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 Opus 4.8 requires paid API access.
- •Claude Opus 4.8 has a 200K context window - 2x larger than GPT-5.5's 128K. Better for long documents and large codebases.
Specs comparison
| Claude Opus 4.8 | GPT-5.5 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓200K | 128K |
| Input / 1M tokens | $15.00 | ✓Free (self-host) |
| Output / 1M tokens | $75.00 | Free (self-host) |
| Release date | 2026-05 | 2026-04 |
Strengths
Claude Opus 4.8
- ✓Best-in-class multi-step reasoning
- ✓Improved instruction following over Opus 4.7
- ✓Reduced refusals on edge-case and nuanced requests
- ✓Superior long-context comprehension at 200K tokens
- ✓Strong scientific and mathematical analysis
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 Opus 4.8 if you need...
- →Complex research and analysis tasks
- →High-stakes code generation
- →Long-document analysis
- →Nuanced reasoning requiring careful judgment
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