Head-to-head · 2026
Claude Opus 4.8 vs GPT-5.5
Verdict. Opus 4.8 leads aggregate intelligence and SWE-Bench Pro; GPT-5.5 wins computer-use, terminal-agent loops, and native voice. The split is real enough to run both.
| Claude Opus 4.8 | GPT-5.5 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2026-05-28 | 2026-04-23 |
| Context | 1M | 1M |
| Max output | 128K | 128K |
| Input /1M | $5.00 | $5.00 |
| Output /1M | $25.00 | $30.00 |
| Modalities | text, vision, code | text, vision, audio, video |
The analysis
These are the two flagship picks of mid-2026. Claude Opus 4.8 tops the aggregate intelligence index — GDPval-AA 1890 and SWE-Bench Pro 69.2% lead the field — with a 1M-token context and unchanged $5/$25 pricing. GPT-5.5 ("Spud") answers with the strongest published computer-use and knowledge-work scores: 84.9% GDPval, 78.7% OSWorld, 98% Tau2 Telecom, and a narrow terminal-agent edge.
Cost is a genuine differentiator. Opus 4.8 held its price; GPT-5.5 doubled output to $30/1M, offset only on output-heavy workloads by a ~40% token-efficiency gain. For most builders, Opus 4.8 is the cheaper path to top-tier reasoning, while GPT-5.5 earns its premium where computer-use autonomy or native voice is the bottleneck.
Honest caveat: GPT-5.5’s SWE-bench Verified and ARC-AGI-2 figures vary across sources and are treated cautiously; Opus 4.8’s GPQA/USAMO numbers lean on Anthropic’s own evals. The coding and GDPval deltas are the well-corroborated ones.
Pick Claude Opus 4.8 if…
- Hardest reasoning and codebase-scale work (SWE-Bench Pro lead)
- You want top-tier capability at unchanged $5/$25
- 1M context with the strongest long-horizon agentic depth
Pick GPT-5.5 if…
- Computer-use / OSWorld automation is the bottleneck
- Terminal-agent and Codex-style autonomous loops
- Native voice is core to the product
Claude Opus 4.8
Modest version bump, real frontier gains — tops the intelligence index at the same price as 4.7.
GPT-5.5
OpenAI’s agentic flagship: best-in-class computer-use and knowledge-work scores, at double the price.