Claude Opus 4.8 vs GPT-5.5
The price-matched flagship fight: Claude Opus 4.8 and GPT-5.5 both cost $5 per million input tokens, which makes this the rare comparison where capability is the only question.
At identical input pricing ($5 per million tokens), Claude Opus 4.8 edges GPT-5.5 on our boards: 63.8% versus 64.3% on CursorBench at their best settings is effectively a tie, but Opus leads the Intelligence Index (61.4 versus 58.9) and is the model Anthropic kept as its reliability workhorse even after Fable 5 launched.
GPT-5.5's real advantage is token efficiency and output price ($30 versus $25 per million favors Opus, but GPT-5.5 tends to spend fewer tokens per task), so real-world task costs land close.
Honest verdict: this one is a coin flip on quality and price; pick the ecosystem you already pay for. Subscribers to ChatGPT get GPT-5.5 effectively bundled; Claude subscribers get Opus the same way.
Prices and context are synced from live provider listings. Deep dives: Claude Opus 4.8 and GPT-5.5.
Best published configuration per model. Every config and source is on the benchmark leaderboards.
Every published configuration for Claude Opus 4.8 and GPT-5.5 on the benchmarks they share, charted side by side. Only these two models are plotted.
SWE-bench Verified
The most-cited agentic coding benchmark: can a model fix a real GitHub issue in a real repository? 500 human-validated tasks, scored by the repo's own tests. Higher is better.
CursorBench 3.1
Ambiguous, multi-file tasks from real Cursor sessions that test codebase understanding, bugfinding, planning, and code review.
DeepSWE
Datacurve's agentic coding benchmark: each model runs as an autonomous agent on real software engineering tasks and is scored on whether its final patch resolves the issue. Higher is better.
FrontierCode Main
Cognition's test of whether a model writes code maintainers would actually merge, not just code that passes tests. Main is the 100 hardest of 150 tasks. Higher is better.
FrontierCode Diamond
The 50 hardest FrontierCode tasks: the toughest production-code problems, graded on whether maintainers would merge the patch. Scores stay low by design. Higher is better.
OSWorld-Verified
The standard computer-use benchmark: agents complete real desktop tasks in a live Ubuntu VM from screenshots, mouse and keyboard, scored by execution-based checks. Higher is better.
BrowseComp
OpenAI's hard web-browsing benchmark: 1,266 questions whose answers are hard to find but easy to verify, requiring persistent multi-step browsing. Higher is better.
Artificial Analysis Intelligence Index
The most-cited composite intelligence score: a 0–100 index combining knowledge, reasoning, math, coding, and agentic evaluations (GPQA Diamond, HLE, IFBench, SciCode, Terminal-Bench Hard, τ²-Bench, and more). Higher is better.
Is Claude Opus 4.8 better than GPT-5.5?
They are the closest-matched flagships we track: CursorBench 3.1 has them within a point of each other (63.8% versus 64.3% at best settings), with Opus ahead on the Intelligence Index (61.4 versus 58.9). At the same $5 per million input price, the deciding factor is usually which subscription you already have.
Which is cheaper to actually run, Opus 4.8 or GPT-5.5?
List prices are nearly identical: both $5 per million input, with Opus cheaper on output ($25 versus $30). In practice GPT-5.5 often uses fewer tokens per task, narrowing the gap. For real workloads, treat them as equally priced and benchmark on your own tasks.
Type
Model comparisonClaude Opus 4.8
Model pageGPT-5.5
Model pageUpdated
June 2026