GPT-6.1 Terra vs Inkling Small
GPT-6.1 Terra leads Inkling Small on coding, 77.4 to 27.3 on the Vibe Coding Index, and Inkling Small costs 4.2x less per output token ($1.20 vs $5.00 per million). Updated October 29, 2026; 19 benchmarks have a result for both.
GPT-6.1 Terra or Inkling Small: which to pick
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 27.3 for Inkling Small.
Pick Inkling Small for output tokens 4.2x cheaper ($1.20 vs $5.00 per million) and work measured by Tax Agent Bench (Vals AI) or Harvey's Legal Agent Benchmark (Vals AI), where it leads.
- Shared results
- 19
- GPT-6.1 Terra only
- 17
- Inkling Small only
- 65
- Like-for-like categories
- 7 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
GPT-6.1 Terra
GPT-6.1 Terra scores 77.4 against 27.3.
4 benchmarks behind each score
Intelligence
AA Intelligence Index
GPT-6.1 Terra
GPT-6.1 Terra leads, 51.0 against 12.9.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Inkling Small has a AA Agentic Index result, 23.5.
Directional only
Reasoning
GPQA Diamond
No call
Only Inkling Small has a GPQA Diamond result, 83.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Inkling Small has a MMLU Pro result, 85.6%.
Directional only
Web design
Design Arena: websites
No call
Only GPT-6.1 Terra has a Design Arena: websites result, 1283.
Directional only
General
Vals Index
GPT-6.1 Terra
GPT-6.1 Terra leads, 60.5% against 27.6%.
Same board, both measured
Long documents
Listed context window
GPT-6.1 Terra
GPT-6.1 Terra takes 1.05M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Inkling Small
GPT-6.1 Terra $0.0035, Inkling Small $0.0010 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Inkling Small has the number, $0.16.
Directional only
At a glance
- Coding index
- GPT-6.1 Terra 77.4 from 4 benchmarks, Inkling Small 27.3 from 4 benchmarks.
- Widest category
- Math, 43.4 points apart on average over 3 shared benchmarks.
- Widest single gap
- FrontierMath, tier 4: GPT-6.1 Terra 92.7% against Inkling Small 17.1%, 75.6 points apart on a 0 to 100 scale.
- Output price
- GPT-6.1 Terra $5.00 against Inkling Small $1.20 per million output tokens, 4.2x apart.
- Context window
- GPT-6.1 Terra takes 1.05M tokens, Inkling Small 524K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | GPT-6.1 Terra | Bars | Inkling Small | Ties |
|---|---|---|---|---|
| Coding | 6 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 2 | ||
| Reasoning | 3 | 0 | ||
| Math | 3 | 0 | ||
| Knowledge | 1 | 0 | ||
| General | 2 | 0 | ||
| All shared boards | 17 | 2 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index60
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| LiveBench coding | 94.3% | Not measured | Only GPT-6.1 Terra measured |
| LMArena WebDev | 1673 | 1409 | GPT-6.1 Terra |
| AA Coding Index | Not measured | 52.9 | Only Inkling Small measured |
| LiveCodeBench (Vals AI) | Not measured | 85.9% | Only Inkling Small measured |
| SWE-bench Verified (Vals AI) | Not measured | 82.2% | Only Inkling Small measured |
| Terminal-Bench 4 (Vals AI) | 49.5% | 0.0% | GPT-6.1 Terra |
| Vibe Code Bench (Vals AI) | 84.0% | 19.1% | GPT-6.1 Terra |
| Code migration (Vals AI) | Not measured | 13.7% | Only Inkling Small measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Inkling Small measured |
| IOI (Vals AI) | Not measured | 9.3% | Only Inkling Small measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 55.1% | Only Inkling Small measured |
| SkillsBench (Vals AI) | Not measured | 33.6% | Only Inkling Small measured |
| CyberBench (Vals AI) | Not measured | 64.1% | Only Inkling Small measured |
| SciCode | 55.1% | 49.7% | GPT-6.1 Terra |
| ALE-Bench | 2608.8 | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text: coding | Not measured | 1451 | Only Inkling Small measured |
| LMArena Text: software and IT | Not measured | 1448 | Only Inkling Small measured |
| LMArena WebDev: React | 1657 | 1399 | GPT-6.1 Terra |
| LMArena WebDev: HTML | 1719 | 1396 | GPT-6.1 Terra |
| LMArena WebDev: from an image | Not measured | 1410 | Only Inkling Small measured |
| Neither model has a result on the other 23 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| AA Intelligence Index | 51.0 | 12.9 | GPT-6.1 Terra |
| Epoch Capabilities Index | Not measured | 150.3 | Only Inkling Small measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 23.5 | Only Inkling Small measured |
| LiveBench research | 73.9% | Not measured | Only GPT-6.1 Terra measured |
| LiveBench browser | 93.1% | Not measured | Only GPT-6.1 Terra measured |
| LiveBench long agentic | 48.6% | Not measured | Only GPT-6.1 Terra measured |
| Finance Agent (Vals AI) | Not measured | 41.3% | Only Inkling Small measured |
| Tax Agent Bench (Vals AI) | 15.2% | 15.4% | Inkling Small |
| Legal Research Bench (Vals AI) | 26.0% | 25.5% | GPT-6.1 Terra |
| Harvey's Legal Agent Benchmark (Vals AI) | 1.7% | 2.9% | Inkling Small |
| Excel Modeling Benchmark (Vals AI) | Not measured | 31.8% | Only Inkling Small measured |
| APEX-Agents | 68.3% | Not measured | Only GPT-6.1 Terra measured |
| MCP Atlas | Not measured | 79.2% | Only Inkling Small measured |
| Neither model has a result on the other 31 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 83.6% | Only Inkling Small measured |
| LiveBench reasoning | 88.7% | Not measured | Only GPT-6.1 Terra measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 89.5% | Only Inkling Small measured |
| Humanity's Last Exam (Artificial Analysis run) | 46.2% | 33.3% | GPT-6.1 Terra |
| GPQA Diamond (Epoch AI run) | 94.3% | 88.5% | GPT-6.1 Terra |
| ARC-AGI | Not measured | 84.0% | Only Inkling Small measured |
| ARC-AGI-2 | Not measured | 40.1% | Only Inkling Small measured |
| Mystery game puzzles | 74.0% | 6.0% | GPT-6.1 Terra |
| EBR-bench | 78.1% | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text: hard prompts | Not measured | 1424 | Only Inkling Small measured |
| LMArena Text: expert | Not measured | 1441 | Only Inkling Small measured |
| LMArena Text: hard prompts in English | Not measured | 1428 | Only Inkling Small measured |
| LMArena Vision: diagrams | Not measured | 1251 | Only Inkling Small measured |
| LMArena Vision: homework | Not measured | 1257 | Only Inkling Small measured |
| Humanity's Last Exam (Scale run) | 35.7% | Not measured | Only GPT-6.1 Terra measured |
| Neither model has a result on the other 8 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | 90.0% | GPT-6.1 Terra |
| FrontierMath, tiers 1 to 3 | 90.9% | 46.3% | GPT-6.1 Terra |
| FrontierMath, tier 4 | 92.7% | 17.1% | GPT-6.1 Terra |
| ProofBench | Not measured | 6.0% | Only Inkling Small measured |
| LMArena Text: math | Not measured | 1458 | Only Inkling Small measured |
| LMArena Text: mathematical work | Not measured | 1440 | Only Inkling Small measured |
| Neither model has a result on the other 8 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 85.6% | Only Inkling Small measured |
| LegalBench (Vals AI) | Not measured | 83.0% | Only Inkling Small measured |
| CorpFin (Vals AI) | Not measured | 69.6% | Only Inkling Small measured |
| TaxEval (Vals AI) | Not measured | 75.5% | Only Inkling Small measured |
| MortgageTax (Vals AI) | Not measured | 62.3% | Only Inkling Small measured |
| MedCode (Vals AI) | Not measured | 37.9% | Only Inkling Small measured |
| SimpleQA Verified | 57.3% | 19.1% | GPT-6.1 Terra |
| LMArena Text: science | Not measured | 1427 | Only Inkling Small measured |
| LMArena Text: medicine and healthcare | Not measured | 1414 | Only Inkling Small measured |
| LMArena Text: legal and government | Not measured | 1414 | Only Inkling Small measured |
| LMArena Text: business and finance | Not measured | 1414 | Only Inkling Small measured |
| Neither model has a result on the other 9 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| Design Arena: websites | 1283 | Not measured | Only GPT-6.1 Terra measured |
| Design Arena: UI components | 1277 | Not measured | Only GPT-6.1 Terra measured |
| Design Arena: game dev | 1348 | Not measured | Only GPT-6.1 Terra measured |
| Design Arena: all code categories | 1295 | Not measured | Only GPT-6.1 Terra measured |
| LiveBench design | 82.3% | Not measured | Only GPT-6.1 Terra measured |
| Neither model has a result on the other 4 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| Vals Index | 60.5% | 27.6% | GPT-6.1 Terra |
| LiveBench data analysis | 82.3% | Not measured | Only GPT-6.1 Terra measured |
| Public Benefits Bench (Vals AI) | Not measured | 59.4% | Only Inkling Small measured |
| MedScribe (Vals AI) | Not measured | 84.1% | Only Inkling Small measured |
| Vals Multimodal Index | Not measured | 50.0% | Only Inkling Small measured |
| Long context reasoning (AA-LCR) | 82.7% | 75.7% | GPT-6.1 Terra |
| Furniture assembly | 79.2% | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text | Not measured | 1414 | Only Inkling Small measured |
| LMArena Text: instruction following | Not measured | 1401 | Only Inkling Small measured |
| LMArena Text: creative writing | Not measured | 1336 | Only Inkling Small measured |
| LMArena Vision | Not measured | 1237 | Only Inkling Small measured |
| LMArena Text: English | Not measured | 1420 | Only Inkling Small measured |
| LMArena Text: non-English | Not measured | 1403 | Only Inkling Small measured |
| LMArena Text: Chinese | Not measured | 1464 | Only Inkling Small measured |
| LMArena Text: German | Not measured | 1404 | Only Inkling Small measured |
| LMArena Text: Japanese | Not measured | 1394 | Only Inkling Small measured |
| LMArena Text: Korean | Not measured | 1374 | Only Inkling Small measured |
| LMArena Text: French | Not measured | 1435 | Only Inkling Small measured |
| LMArena Text: Spanish | Not measured | 1427 | Only Inkling Small measured |
| LMArena Text: Russian | Not measured | 1396 | Only Inkling Small measured |
| LMArena Text: Polish | Not measured | 1428 | Only Inkling Small measured |
| LMArena Text: multi-turn | Not measured | 1416 | Only Inkling Small measured |
| LMArena Text: longer queries | Not measured | 1404 | Only Inkling Small measured |
| LMArena Text: writing and language | Not measured | 1358 | Only Inkling Small measured |
| LMArena Text: entertainment and media | Not measured | 1353 | Only Inkling Small measured |
| LMArena Vision: English | Not measured | 1243 | Only Inkling Small measured |
| LMArena Vision: Chinese | Not measured | 1292 | Only Inkling Small measured |
| LMArena Vision: reading text | Not measured | 1243 | Only Inkling Small measured |
| LMArena Vision: humor | Not measured | 1207 | Only Inkling Small measured |
| LMArena Vision: creative writing | Not measured | 1205 | Only Inkling Small measured |
| MultiChallenge | 74.2% | Not measured | Only GPT-6.1 Terra measured |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-6.1 Terra | Inkling Small | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Inkling Small costs less
Repository review
50K input + 3K output tokens
Inkling Small costs less
Agent loop
200K input + 10K output tokens
Inkling Small costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | OpenAI GPT-6.1 Terra | Thinking Machines Inkling Small |
|---|---|---|
| Maker | OpenAI | Thinking Machines |
| Weights | No public weights listed | Open weights |
| Released | October 26, 2026 | July 30, 2026 |
| Context window | 1.05M | 524K |
| Input $/Mtok | $1.00 | $0.45 |
| Output $/Mtok | $5.00 | $1.20 |
| Coding index | 77.4 | 27.3 |
| Independent measurements behind it | 4 | 4 |
| Cost per solved task | Not computable | $0.16 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6.1 Terra better than Inkling Small for coding?
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 27.3 for Inkling Small. Pick Inkling Small for output tokens 4.2x cheaper ($1.20 vs $5.00 per million) and work measured by Tax Agent Bench (Vals AI) or Harvey's Legal Agent Benchmark (Vals AI), where it leads.
Which is cheaper, GPT-6.1 Terra or Inkling Small?
GPT-6.1 Terra costs $1.00 per million input tokens and $5.00 per million output tokens; Inkling Small costs $0.45 and $1.20. Cost per solved task is known for Inkling Small only.
Which has the bigger context window, GPT-6.1 Terra or Inkling Small?
GPT-6.1 Terra, with 1.05M tokens against 524K.
How many benchmarks is the GPT-6.1 Terra vs Inkling Small comparison based on?
19 benchmarks have a result for both models as of October 29, 2026. GPT-6.1 Terra's coding index rests on 4 independent benchmarks and Inkling Small's on 4. Where only one model has a result, the page says so instead of naming a winner.