GPT-6.1 Terra vs GPT-6 Sol
| Spec | GPT-6.1 Terra | GPT-6 Sol |
|---|---|---|
| Respan Index | 68.9 (#9) | 64.7 (#11) |
| Blended price per 1M | $1 | $2 |
| Context window | 1.1M | 1.1M |
| Input / output per 1M | $0.5 / $2.5 | $1 / $5 |
| Max output | 128K | 128K |
| Input | text, vision | text, vision |
| Released | 2026-10-26 | 2026-09-22 |
Respan Index by category
Each category is scored 0 to 100, and how far ahead the winner is. Leads under a point are close to even.
| Category | GPT-6.1 Terra | GPT-6 Sol |
|---|---|---|
| Coding | 57.9 GPT-6.1 Terra | 51.8 GPT-6 Sol |
| Agents | 77.0 GPT-6.1 Terra | 71.0 GPT-6 Sol |
| Reasoning | 83.0 GPT-6.1 Terra | 77.0 GPT-6 Sol |
| Knowledge & language | 57.4 GPT-6.1 Terra | 60.6 GPT-6 Sol |
| Human preference | 57.9 GPT-6.1 Terra | 57.8 GPT-6 Sol |
Benchmarks both report
GPT-6.1 Terra leads on 8 of the 13 benchmarks both report. Higher is better. Each score links to where it was published.
| Benchmark | GPT-6.1 Terra | GPT-6 Sol |
|---|---|---|
| APEX-Agents (Mercor) | 68.3% | 54.3% |
| Vending-Bench 2 (Andon Labs) | 9107.46 | 14427.85 |
| EBR-bench (Epoch AI) | 78.1% | 53.3% |
| FrontierMath Tier 4 v2 (Epoch AI) | 92.7% | 90% |
| FrontierMath Tiers 1-3 v2 (Epoch AI) | 90.9% | 89.8% |
| Furniture Assembly (Epoch AI) | 79.2% | 58.3% |
| GPQA Diamond | 94.3% | 94.3% |
| LMArena Agent (LMArena) | 0.1057 | 0.0796 |
| LMArena WebDev (LMArena) | 1673 | 1678 |
| Mystery Game Puzzles (Epoch AI) | 74% | 56% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 100% | 100% |
| SimpleQA Verified | 57.3% | 60.7% |
| Terminal-Bench 4.0 (Vals AI) | 49.5% | 44.4% |
FAQ
Is GPT-6.1 Terra better than GPT-6 Sol?
GPT-6.1 Terra scores 68.9 on the Respan Index (#9), ahead of GPT-6 Sol at 64.7 (#11). GPT-6.1 Terra leads on 8 of the 13 benchmarks both report.
Which is cheaper, GPT-6.1 Terra or GPT-6 Sol?
GPT-6.1 Terra lists at $0.5 input and $2.5 output per 1M tokens; GPT-6 Sol at $1 and $5. GPT-6.1 Terra is 2.0x cheaper per token at list price.
Which has the larger context window?
Both accept 1.1M tokens of context.