The legitimate free route is ChatGPT: sign in or create a free account, open a new chat, and select GPT 5.5 if it appears.
For API procurement, long context agents or enterprise deployment, Claude Opus 4.7 is easier to evaluate from public documentation: Anthropic lists a 1M context window with no long context premium, multi clo...
There is not enough same condition public data to declare an overall winner: Opus 4.7 leads GDPval AA at 1,753 Elo, while GPT 5.5 high, low and non reasoning score 59, 51 and 41 on the Artificial Analysis In...
Claude Opus 4.7 is the better supported first trial for coding and tool heavy agents: Vellum reports 87.6% on SWE bench Verified and 77.3% on MCP Atlas.
Claude Opus 4.7 is easier to put into an API proof of concept now: Anthropic lists API and cloud platform availability, $5/$25 per million input/output token pricing, a 1M context window and documented long...
No reliable winner can be named: Claude Opus 4.7 is verified in Anthropic’s documentation, while GPT 5.5 Spud is not verified here by a primary OpenAI source.
There is no defensible single champion because the cited numbers come from different harnesses, source layers and tool settings.
The fastest official routes to try GPT 5.5 are ChatGPT and Codex. OpenAI says API availability is still “coming soon.” [1][20]
There is no clean overall winner from public benchmarks alone. GPT 5.5 leads the cited Terminal Bench 2.0 numbers at 82.7%, while Claude Opus 4.7 leads SWE Bench Pro at 64.3% and SWE Bench Verified at 87.6%...
AWS reports Claude Opus 4.7 at 87.6% on SWE bench Verified, based on Anthropic data, making it the standout public figure for agentic coding use cases [7].
The main public benchmark numbers are 87.6% on SWE bench Verified, 94.2% on GPQA and 80.5% on SWE bench Multilingual.
The most cited Claude Mythos Preview benchmark result is 93.9% on SWE bench, a software engineering evaluation that is most relevant to coding tasks and agent style workflows [1][2].