--- title: "Is GPT-5.6 Terra still undominated? · Undominated.ai" canonical: https://undominated.ai/check/openai__gpt-5.6-terra/ description: "GPT-5.6 Terra: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 23, 2026. Unrated stays unrated." --- # Is GPT-5.6 Terra still undominated? · Undominated.ai > GPT-5.6 Terra: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 23, 2026. Unrated stays unrated. # Is GPT-5.6 Terra a good deal? Whether anything in this catalogue beats GPT-5.6 Terra on both quality and price, and what you give up if it does. A computation on the current catalogue, not an opinion. 13 undominated of 136 · Sep 23, 2026 [1 · Choose & set workload](#check-input)[2 · Read verdict](#check-verdict)[3 · Inspect alternatives](#check-options) As of Sep 23, 2026, GPT-5.6 Terra is dominated for Balanced on LMArena. GPT-5.6 Sol scores 8.9 higher and costs 11% less, with a covering envelope. 13 of 136 rated, priced standard models are undominated. [Inspect model evidence](/models/openai__gpt-5.6-terra/) [Compare differences & requirements](/compare/?models=openai%2Fgpt-5.6-terra%2Copenai%2Fgpt-5.6-sol) Current model GPT-5.6 Terra 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) GPT-5.6 Sol is both better and cheaper than GPT-5.6 Terra: 8.9 points higher on LMArena and 11% less per million tokens, $0.50 cheaper at this mix. [GPT-5.6 Terra](https://undominated.ai/models/openai__gpt-5.6-terra/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1446.2 Effective $/M · Balanced · lower is better ** $4.50/M [GPT-5.6 Sol](https://undominated.ai/models/openai__gpt-5.6-sol/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1455.1 Effective $/M · Balanced · lower is better ** $4.00/M GPT-5.6 Terra 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 136 rated, priced models on this lens: 1 model dominates it and gives up nothing, 5 more dominate it but give something up. GPT-5.6 Terra scores 1446.2 at $4.50 per million tokens for this mix. ## Envelope-safe replacements Each row scores at least as high, costs no more, and covers this model’s context, output, modalities, tools, and reasoning. A cheaper narrower model is not listed here. | Model | LMArena | Effective $/M | You save | | --- | --- | --- | --- | | [GPT-5.6 Sol](/models/openai__gpt-5.6-sol/) | 1455.1 +8.9 | $4.00/M | 11% | ## 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 | | --- | --- | --- | --- | | [Gemini 3.8 Flash](/models/google__gemini-3.8-flash/) | 1494.7 | $1.50/M | context, max output | | [Gemini 3.7 Flash](/models/google__gemini-3.7-flash/) | 1490.5 | $1.50/M | context, max output | | [Muse Spark 1.3](/models/meta__muse-spark-1.3/) | 1489.7 | $2.00/M | context | | [Muse Spark 1.1](/models/meta__muse-spark-1.1/) | 1480.2 | $2.00/M | context | | [Gemini 3.1 Pro Preview](/models/google__gemini-3.1-pro-preview/) | 1480.1 | $4.50/M | context, max output | 136 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/)