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GPT-6.1 Terra vs GPT-6 Luna
GPT-6.1 Terra scores higher than GPT-6 Luna on all 3 public leaderboards that rate both. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, GPT-6.1 Terra is at 75 and GPT-6 Luna at 26.9 (out of 100).
Scores as published by each board; table composed October 28, 2026.
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Leaderboard by leaderboard
| Board | GPT-6.1 Terra | GPT-6 Luna | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,670.7 | 1,579.8 | GPT-6.1 Terra |
| Vals AI Vals Index accuracy % · weighted finance + coding tasks | 60.2 | 52.3 | GPT-6.1 Terra |
| Artificial Analysis intelligence index · measured runs only | 51 | 27.8 | GPT-6.1 Terra |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
GPT-6.1 Terra at a glance
- Developer
- OpenAI
- Status
- Live since October 26, 2026
- API price
- $1 input / $5 output per 1M tokens · OpenAI, gpt-6.1-terra
- Context window
- 1.05M tokens
Live — Oct 26 · $1 / $5 per MTok, cached input $0.05, cache writes $1.25 (OpenAI's model page) · 1.05M ctx / 128K out · knowledge cutoff Jun 1, 2026 · reasoning, text and image in · GPT-5.6 Terra lists at $2 / $12 on OpenRouter · first seen Oct 16-19 as the judge model in Microsoft's dotnet/efcore eval configs (PR #39217) · our sweep caught gpt-6.1-terra at 17:52 UTC and fired at 17:53 · OpenRouter added openai/gpt-6.1-terra (18:13 UTC) and openai/gpt-6.1-terra-pro (18:15) the same evening, both at $1 / $5 and 1.05M ctx · scored on LMArena, Vals and Artificial Analysis by Oct 28.
GPT-6.1 Terra is live in OpenAI's API at $1 / $5 per million tokens, under GPT-5.6 Terra's $2 / $12
2026-10-26 · OpenAI's GPT-6.1 Terra is live in its API. Our radar saw the gpt-6.1-terra id at 17:52 UTC on October 26 and fired the alert at 17:53, before OpenRouter listed it.
GPT-6.1 Terra turns up again, as a cheaper reviewer in a GitHub engineer's Copilot workflow
2026-10-25 · A second public repo now calls GPT-6.1 Terra, a model OpenAI has not announced. On October 24 at 03:48 UTC, Nate Finch, whose GitHub profile lists his company as GitHub, merged a pull request in his own public repo, natefinch/council4, that moves every review step from gpt-6.1-sol to gpt-6.1-terra at high effort.
GPT-6 Luna at a glance
- Developer
- OpenAI
- Status
- Live since September 22, 2026
- API price
- $0.10 input / $0.50 output per 1M tokens · OpenAI, gpt-6-luna
- Context window
- 1.05M tokens
Live — Sep 22, in the API and ChatGPT (Free and Go too) the same day · the cheap, high-volume tier · models.dev lists gpt-6-luna on OpenAI's own API (read Sep 24).
OpenAI opens the Decisions API: GPT-6 Luna returns probabilities, choices and scores for $0.10 per million input tokens
2026-10-06 · OpenAI has opened a public beta of the Decisions API, a new endpoint (POST /v1/decisions) where the model answers a question about your input with a number or a label instead of writing text. GPT-6 Luna is the only model it runs.
GPT-6.1 Terra vs GPT-6 Luna: quick answers
Which is better, GPT-6.1 Terra or GPT-6 Luna?
It depends on what you measure. GPT-6.1 Terra scores higher than GPT-6 Luna on all 3 public leaderboards that rate both. GPT-6.1 Terra's widest lead is on Artificial Analysis. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, GPT-6.1 Terra is at 75 and GPT-6 Luna at 26.9 (out of 100).
Which is newer, GPT-6.1 Terra or GPT-6 Luna?
GPT-6.1 Terra. It went live on October 26, 2026, 34 days after GPT-6 Luna (September 22, 2026).
Which is cheaper, GPT-6.1 Terra or GPT-6 Luna?
GPT-6 Luna is cheaper on both input and output. On each vendor's own API, GPT-6.1 Terra is $1 input / $5 output per million tokens and GPT-6 Luna is $0.10 input / $0.50 output per million tokens. GPT-6.1 Terra's rate rises for prompts over 272K tokens; GPT-6 Luna's rate rises for prompts over 272K tokens. Prices as published in the models.dev catalog, as of 2026-10-27.
Which has the bigger context window, GPT-6.1 Terra or GPT-6 Luna?
Neither. Both take 1.05M tokens.
Who makes GPT-6.1 Terra and GPT-6 Luna?
Both are from OpenAI.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed October 28, 2026). Boards measure different things, so raw scores are only comparable within a row.
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