--- title: "Is GPT-5.5 still undominated? · Undominated.ai" canonical: https://undominated.ai/check/openai__gpt-5.5/ description: "GPT-5.5: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Oct 6, 2026. Unrated stays unrated." --- # Is GPT-5.5 still undominated? · Undominated.ai > GPT-5.5: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Oct 6, 2026. Unrated stays unrated. # Is GPT-5.5 a good deal? Whether anything in this catalogue beats GPT-5.5 on both quality and price, and what you give up if it does. A computation on the current catalogue, not an opinion. 12 undominated of 145 · Oct 6, 2026 [1 · Choose & set workload](#check-input)[2 · Read verdict](#check-verdict)[3 · Inspect alternatives](#check-options) As of Oct 6, 2026, Claude Opus 5.5 scores higher and costs less than GPT-5.5 for Balanced on LMArena, but it is not a drop-in. You would give up: context. [Inspect model evidence](/models/openai__gpt-5.5/) [Compare differences & requirements](/compare/?models=openai%2Fgpt-5.5%2Canthropic%2Fclaude-opus-5.5) Current model GPT-5.5 Balanced 3 tokens in per 1 out Balanced Summarise Chat Code gen Agentic Monthly spend (USD) Used only to say how many months a named switching cost would take to earn back. Leave blank to skip. Switching cost (USD) Claude Opus 5.5 scores 44.9 points higher and costs 29% less, but you would give up: context. [GPT-5.5](https://undominated.ai/models/openai__gpt-5.5/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1466.8 Effective $/M · Balanced · lower is better ** $11.25/M [Claude Opus 5.5](https://undominated.ai/models/anthropic__claude-opus-5.5/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1511.7 Effective $/M · Balanced · lower is better ** $8.00/M GPT-5.5 takes file, image, text, returns up to 128,000 tokens from a 1,050,000-token context, and is listed by 7 sellers. Compared against 145 rated, priced models on this lens: nothing dominates it outright, 5 more dominate it but give something up. GPT-5.5 scores 1466.8 at $11.25 per million tokens for this mix. ## Higher score, lower price, named losses Not a drop-in. The loss is why these are not a recommendation. | Model | LMArena | Effective $/M | You give up | | --- | --- | --- | --- | | [Claude Opus 5.5](/models/anthropic__claude-opus-5.5/) | 1511.7 | $8.00/M | context | | [Claude Opus 4.6](/models/anthropic__claude-opus-4.6/) | 1503.2 | $10.00/M | context | | [Claude Opus 5](/models/anthropic__claude-opus-5/) | 1502.1 | $10.00/M | context | | [Gemini 3.8 Flash](/models/google__gemini-3.8-flash/) | 1497.0 | $3.00/M | context, max output | | [MiMo-V2.6-Pro](/models/xiaomi__mimo-v2.6-pro/) | 1491.0 | $0.540/M | file | 145 rated, priced standard models. Chartreuse is the frontier. Cobalt is the model you named, when it is not on the staircase. Copy watch URL [Open the frontier](/frontier/) The link keeps the model and mix, using the current catalogue. Monthly spend and switching cost stay in this browser tab and are left out of the link. ## Saved decision references Save the model, workload, catalogue date and capability-preservation rule in this browser. Spend, switching cost and bill contents are not saved. No account or notifications. Constraint: replacements must preserve the model’s capabilities; any losses remain named trade-offs. Historical decisions cannot be fully replayed from saved references: past prices, scores and capability evidence are not stored. Save this reference ## Continue your investigation - [Build a shortlist](/compare/) - [Inspect alternatives](/alternatives/) - [Check billing conditions](/traps/) - [Read model evidence](/models/)