Claude Sonnet 5 vs GPT-6 Astra.
Verdict by category, tale of the tape, shared benchmarks only, and cost at three workloads — all from the tracked data.
Verdict by category
| Category | Claude Sonnet 5 | GPT-6 Astra | Winner |
|---|---|---|---|
| League Score | 73.9 | 96.7 | GPT-6 Astra |
| Coding (SWE-bench %) | 85.2 | — | — |
| Reasoning (GPQA %) | — | 96.0 | — |
| Context (tokens) | 1000000 | 1050000 | GPT-6 Astra |
| Speed (tok/s) | — | — | — |
| Price (blended $/1M) | $4.00 | $20.00 | Claude Sonnet 5 (cheaper) |
Tale of the tape
| Spec | Claude Sonnet 5 | GPT-6 Astra |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Released | Jun 30, 2026 | Sep 3, 2026 |
| League Score | 74 | 97 |
| Context | 1,000,000 tokens | 1,050,000 tokens |
| Max output | 128,000 | 128,000 |
| $/1M input | $2.00 | $10.00 |
| $/1M output | $10.00 | $50.00 |
| Weights | Closed | Closed |
| Speed | — | — |
Head-to-head benchmarks (shared only)
| Benchmark | Claude Sonnet 5 | GPT-6 Astra |
|---|---|---|
| LiveBench overall | 74.6 | 86.1 |
Cost at three workloads
| Workload | Claude Sonnet 5 | GPT-6 Astra |
|---|---|---|
| Light — 1M in / 250K out | $4.50 | $22.50 |
| Standard — 10M in / 2.5M out | $45.00 | $225.00 |
| Long-context — 50M in / 5M out | $150.00 | $750.00 |
The pick
Pick Claude Sonnet 5 if you want the lower running cost; coding is the priority.
Pick GPT-6 Astra if you want the higher overall League Score; you need the bigger context window.
All figures from the model database — sources and dates on each model page. Cost your own workload or compare a different pair.
Frequently asked questions
Which is better overall, Claude Sonnet 5 or GPT-6 Astra?
GPT-6 Astra leads on overall League Score, 97 to 74 — a gap of 23 points on a composite of sourced benchmarks. That is overall form, not every category: check the per-category verdicts before choosing.
Which is cheaper, Claude Sonnet 5 or GPT-6 Astra?
Claude Sonnet 5 is cheaper: $4.00 vs $20.00 blended per 1M tokens (3:1 input/output mix) — about 5.0x less per token.
Which has the bigger context window, Claude Sonnet 5 or GPT-6 Astra?
GPT-6 Astra, with 1.1M of context against 1M for Claude Sonnet 5.
Are Claude Sonnet 5 and GPT-6 Astra open source?
Claude Sonnet 5 is closed weights — API access only; GPT-6 Astra is closed weights — API access only.