Claude Sonnet 4.5 vs GPT-5.6 Sol benchmark

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Frequently Asked Questions

Which is better overall, Claude Sonnet 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol has the higher preference Elo in our latest snapshot (1,608). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, Claude Sonnet 4.5 or GPT-5.6 Sol?

GPT-5.6 Sol leads SWE-bench at 77.6% vs 70.1%. SWE-bench is one harness, not your repo.

Which is cheaper to run in production?

Claude Sonnet 4.5 output tokens are $15/1M versus $30/1M. Input prices and retry rates still move the real bill.

Which is faster, Claude Sonnet 4.5 or GPT-5.6 Sol?

Claude Sonnet 4.5 has the lower time-to-first-token (240 ms vs 270 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

GPT-5.6 Sol accepts 1.1M tokens versus 1M.

Can I self-host either model?

Neither model is marked open-weights here. You are comparing hosted APIs.

Are these scores from CompareLLM’s own evals?

No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.

What does preference Elo mean on this page?

Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4.5 and GPT-5.6 Sol Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.