Model comparison
GPT-5.6 Terra vs Inkling
GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 44.1 on the Noometry Index. Inkling costs 1.7× less per token, which makes it the better buy when GPT-5.6 Terra's lead doesn't matter for your workload.
Last verified . 39 shared benchmarks.
Summary
- They share 39 benchmarks with published results for both. GPT-5.6 Terra scores higher in 9 categories and Inkling in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5.6 Terra leads 81.6 to 31.3.
- The biggest single-benchmark swing is ProofBench: 74% for GPT-5.6 Terra and 0% for Inkling.
- Inkling is cheaper at $1.87 / $4.68 per million input/output tokens, against $2 / $12 for GPT-5.6 Terra.
- GPT-5.6 Terra accepts more context: 1.05M tokens versus 66K.
- Inkling has downloadable open weights; the other is API-only.
Side by side
| GPT-5.6 Terra | Inkling | |
|---|---|---|
| Provider | OpenAI | Thinking Machines Lab |
| Noometry Index | 59.2 | 44.1 |
| Released | 2026-07-09 | 2026-07-15 |
| Weights | Proprietary | Open |
| Context window | 1.05M | 66K |
| Max output | 128K | 66K |
| Input $ / M tokens | $2 | $1.87 |
| Output $ / M tokens | $12 | $4.68 |
| Results tracked | 52 | 41 |
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Category by category
Coding GPT-5.6 Terra leads
GPT-5.6 Terra: 57.7 (#19), Inkling: 34.5 (#234)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| FrontierCode | 41.3% | 14% |
| LMArena WebDev | 1522 | 1413 |
| SciCode | 55% | 47% |
| WeirdML | 78.3% | 32.3% |
| LMArena Coding | 1484 | 1464 |
| ALE-Bench | 1,951 | 946 |
| DeepSWE | 69.6% | — |
| CursorBench | 41.3% | — |
| FrontierSWE | — | 4.1% |
Agentic & Tool Use GPT-5.6 Terra leads
GPT-5.6 Terra: 40.1 (#25), Inkling: 29.6 (#85)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| APEX-Agents | 58.2% | 33.8% |
| τ²-bench Banking | — | 25% |
| BALROG | 53.2% | — |
| GDP.pdf | 24.7% | — |
| Vending-Bench 2 | 7,343 | — |
Reasoning GPT-5.6 Terra leads
GPT-5.6 Terra: 60.7 (#21), Inkling: 40.4 (#56)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| ARC-AGI-2 | 83.9% | 36.5% |
| SimpleBench | 48.9% | 50% |
| ARC-AGI-1 | 96.5% | 79.5% |
| CritPt | 30% | 5.4% |
| Chess Puzzles | 54% | 21% |
| LMArena Hard Prompts | 1468 | 1451 |
| DTBench | 93.3% | 87.5% |
| LMCA | 55% | 37.6% |
| Epoch Capabilities Index | 159.62 | 148.54 |
| Kagi LLM Benchmark | 51.3% | — |
| NYT Connections (extended) | 78.4% | — |
| Mystery Game Puzzles | 35% | — |
| Surface Evolver Bench | 83.8% | — |
Math GPT-5.6 Terra leads
GPT-5.6 Terra: 81.6 (#12), Inkling: 31.3 (#225)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| FrontierMath (Tiers 1-3) | 86% | 33.3% |
| FrontierMath Tier 4 | 70.7% | 4.9% |
| OTIS Mock AIME 2024-2025 | 99.7% | 88.9% |
| ProofBench | 74% | 0% |
| LMArena Math | 1466 | 1479 |
Knowledge GPT-5.6 Terra leads
GPT-5.6 Terra: 61.2 (#30), Inkling: 55.1 (#49)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| GPQA Diamond | 93.3% | 88.3% |
| SimpleQA Verified | 43.2% | 40.3% |
| LMArena Expert | 1492 | 1465 |
Multimodal Not comparable
GPT-5.6 Terra: 47.3 (#11), Inkling: —
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| LMArena Vision | 1271 | — |
| Blueprint-Bench 2 | 30.8% | — |
| Furniture Assembly | 54.2% | — |
| LMArena Document | 1472 | — |
Multilingual Too close to call
GPT-5.6 Terra: 54.4 (#44), Inkling: 54.0 (#52)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| LMArena Non-English | 1439 | 1434 |
| LMArena Chinese | 1513 | 1490 |
| LMArena French | 1471 | 1458 |
| LMArena German | 1460 | 1446 |
| LMArena Japanese | 1457 | 1429 |
| LMArena Korean | 1425 | 1404 |
| LMArena Russian | 1450 | 1429 |
| LMArena Spanish | 1448 | 1448 |
Instruction Following GPT-5.6 Terra leads
GPT-5.6 Terra: 76.4 (#40), Inkling: 75.1 (#71)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| LMArena Instruction Following | 1454 | 1426 |
Long Context Too close to call
GPT-5.6 Terra: 44.4 (#68), Inkling: 43.8 (#86)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| LMArena Longer Query | 1451 | 1434 |
Writing & Preference GPT-5.6 Terra leads
GPT-5.6 Terra: 70.2 (#23), Inkling: 65.2 (#51)
| Benchmark | GPT-5.6 Terra | Inkling |
|---|---|---|
| LMArena Text | 1447 | 1441 |
| LMArena Creative Writing | 1410 | 1387 |
| EQ-Bench Creative Writing | 1855 | 1611 |
| EQ-Bench 4 | 1234 | 1226 |
| LMArena Multi-Turn | 1449 | 1436 |
Frequently asked questions
Is GPT-5.6 Terra better than Inkling?
GPT-5.6 Terra is the stronger model overall, scoring 59.2 to 44.1 on the Noometry Index. Inkling costs 1.7× less per token, which makes it the better buy when GPT-5.6 Terra's lead doesn't matter for your workload.
Which is cheaper, GPT-5.6 Terra or Inkling?
Inkling is cheaper. It lists at $1.87 per million input tokens and $4.68 per million output tokens; GPT-5.6 Terra lists at $2 and $12.
Is GPT-5.6 Terra or Inkling better for coding?
GPT-5.6 Terra scores higher on coding benchmarks: 57.7 versus 34.5 in the Noometry coding category.
Which has the bigger context window?
GPT-5.6 Terra does, with 1.05M tokens against 66K.
How many benchmarks do GPT-5.6 Terra and Inkling share?
39 benchmarks have published results for both models. GPT-5.6 Terra has 52 scored results on Noometry and Inkling has 41.