Head-to-head for fiction
GPT-6.1 Terra vs GPT-6.1 Sol for fiction writing
Both are on WriteWithPaige, so you can try them on the same scene and keep the reply you like. GPT-6.1 Terra (OpenAI): OpenAI's newest. Half the credits of Sol, with faster replies. GPT-6.1 Sol (OpenAI): Fast, sharp and clean. A great everyday choice. GPT-6.1 Terra usually uses fewer credits (about 16–45 a chat reply against 32–89 for GPT-6.1 Sol).
Updated October 26, 2026
Side by side
| Detail | GPT-6.1 Terra | GPT-6.1 Sol |
|---|---|---|
| Made by | OpenAI | OpenAI |
| Released | October 26, 2026(OpenAI: Introducing GPT-6.1 Terra) | September 29, 2026(OpenAI: GPT-6.1 Sol system card) |
| Context window | About 1 million tokens (1,050,000)(OpenAI: GPT-6.1 Terra model docs) | About 1 million tokens (1,050,000)(OpenAI: GPT-6.1 Sol model docs) |
| Group on WriteWithPaige | Strong all-rounder | Strong all-rounder |
| In one line | OpenAI's newest. Half the credits of Sol, with faster replies. | Fast, sharp and clean. A great everyday choice. |
| Good for | OpenAI says it finishes tasks over three times faster than GPT-6.1 Sol, at half the price per token.(OpenAI: Introducing GPT-6.1 Terra) | Close to GPT-6 Astra for much less, so it is a sensible everyday OpenAI choice.(OpenAI: latest model guide) |
| Weaker at | OpenAI still points to GPT-6.1 Sol and GPT-6 Astra for its hardest work; Terra is built for speed and cost.(OpenAI: Introducing GPT-6.1 Terra) | In a blind style test, judges found Claude Opus 5.5 more varied and more metaphorical in almost every comparison.(Artificial Analysis: GPT-6.1 Sol vs Claude Opus 5.5) |
| Credits: chat reply | About 16–45 | About 32–89 |
| Credits: continue a chapter | About 18–54 | About 36–107 |
| Credits: new chapter | About 20–56 | About 40–112 |
The fair test: same scene, both models
Benchmarks don't tell you which voice fits your book. Your own chapter does.
- Open a chapter you know well and pick GPT-6.1 Terra. Ask for the next scene.
- Pick GPT-6.1 Sol and ask for the same scene again, in the same words.
- Read both out loud. Keep the one that sounds like your book, then switch back to Paige for everyday drafting.
Frequently asked questions
GPT-6.1 Terra or GPT-6.1 Sol: which is better for fiction?
Both are on WriteWithPaige, so you can try them on the same scene and keep the reply you like. GPT-6.1 Terra (OpenAI): OpenAI's newest. Half the credits of Sol, with faster replies. GPT-6.1 Sol (OpenAI): Fast, sharp and clean. A great everyday choice. GPT-6.1 Terra usually uses fewer credits (about 16–45 a chat reply against 32–89 for GPT-6.1 Sol).
Can I switch between GPT-6.1 Terra and GPT-6.1 Sol in the same story?
Yes. Pick a model before any reply. Your chapters and Story Bible stay the same, so the next model picks up where the last one left off. Switch back to Paige whenever you like.
Will either model write everything I ask?
No promises. Each follows its maker's content rules and may turn down some requests or tone a scene down. Paige is always there and is included in your plan.
How do credits work?
Paige is included in every plan. Other models use credits, sold in packs from US$10 (€10 in the eurozone) for 1,000 credits. Each reply uses credits based on how much of your story the model reads and writes, and shows what it used.
Keep exploring
Write fiction with GPT-6.1 Terra
OpenAI's newest. Half the credits of Sol, with faster replies.
Write fiction with GPT-6.1 Sol
Fast, sharp and clean. A great everyday choice.
All AI models
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AI fiction writer
How Paige drafts, continues and edits a novel with you.
Best AI tools for fiction
How the main AI writing tools compare for novelists.
Plans and pricing
What each plan includes. Paige comes with every plan.
Sources
Facts about each model come from its maker and the reviews below. Credit ranges come from WriteWithPaige. We don't publish our own benchmark scores.
Try both on your own chapter
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