GPT-6.1 Terra vs Grok 4.5
GPT-6.1 Terra leads Grok 4.5 on coding, 77.4 to 52.3 on the Vibe Coding Index, and GPT-6.1 Terra costs 1.2x less per output token ($5.00 vs $6.00 per million). Updated October 29, 2026; 22 benchmarks have a result for both.
GPT-6.1 Terra or Grok 4.5: which to pick
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 52.3 for Grok 4.5, though on 4 benchmarks against 5.
Pick Grok 4.5 for work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.
- Shared results
- 22
- GPT-6.1 Terra only
- 14
- Grok 4.5 only
- 95
- 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 52.3.
4 and 5 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only GPT-6.1 Terra has a AA Intelligence Index result, 51.0.
Directional only
Agentic work
AA Agentic Index
No call
Only Grok 4.5 has a AA Agentic Index result, 41.2.
Directional only
Reasoning
GPQA Diamond
No call
Only Grok 4.5 has a GPQA Diamond result, 92.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Grok 4.5 has a MMLU Pro result, 89.2%.
Directional only
Web design
Design Arena: websites
GPT-6.1 Terra
GPT-6.1 Terra leads, 1283 against 1280.
Same board, both measured
General
Vals Index
No call
Only GPT-6.1 Terra has a Vals Index result, 60.5%.
Directional only
Long documents
Listed context window
GPT-6.1 Terra
GPT-6.1 Terra takes 1.05M tokens against 500K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-6.1 Terra
GPT-6.1 Terra $0.0035, Grok 4.5 $0.0050 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Grok 4.5 has the number, $0.62.
Directional only
At a glance
- Coding index
- GPT-6.1 Terra 77.4 from 4 benchmarks, Grok 4.5 52.3 from 5 benchmarks.
- Widest category
- Math, 34.7 points apart on average over 3 shared benchmarks.
- Widest single gap
- FrontierMath, tier 4: GPT-6.1 Terra 92.7% against Grok 4.5 24.4%, 68.3 points apart on a 0 to 100 scale.
- Output price
- GPT-6.1 Terra $5.00 against Grok 4.5 $6.00 per million output tokens, 1.2x apart.
- Context window
- GPT-6.1 Terra takes 1.05M tokens, Grok 4.5 500K.
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 | Grok 4.5 | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Agentic work | 1 | 2 | ||
| Reasoning | 2 | 0 | ||
| Math | 3 | 0 | ||
| Knowledge | 1 | 0 | ||
| Web design | 4 | 0 | ||
| General | 2 | 0 | ||
| All shared boards | 20 | 2 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| LiveBench coding | 94.3% | Not measured | Only GPT-6.1 Terra measured |
| LMArena WebDev | 1673 | 1553 | GPT-6.1 Terra |
| AA Coding Index | Not measured | 72.4 | Only Grok 4.5 measured |
| LiveCodeBench (Vals AI) | Not measured | 87.3% | Only Grok 4.5 measured |
| SWE-bench Verified (Vals AI) | Not measured | 86.6% | Only Grok 4.5 measured |
| Terminal-Bench 4 (Vals AI) | 49.5% | 8.6% | GPT-6.1 Terra |
| Vibe Code Bench (Vals AI) | 84.0% | 69.0% | GPT-6.1 Terra |
| Code migration (Vals AI) | Not measured | 36.6% | Only Grok 4.5 measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Grok 4.5 measured |
| IOI (Vals AI) | Not measured | 40.6% | Only Grok 4.5 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 67.8% | Only Grok 4.5 measured |
| SkillsBench (Vals AI) | Not measured | 66.0% | Only Grok 4.5 measured |
| CyberBench (Vals AI) | Not measured | 71.0% | Only Grok 4.5 measured |
| SciCode | 55.1% | 55.0% | GPT-6.1 Terra |
| FrontierCode | Not measured | 42.4% | Only Grok 4.5 measured |
| WeirdML | Not measured | 46.4% | Only Grok 4.5 measured |
| MirrorCode | Not measured | 32.2% | Only Grok 4.5 measured |
| ALE-Bench | 2608.8 | 1309.3 | GPT-6.1 Terra |
| LMArena Text: coding | Not measured | 1474 | Only Grok 4.5 measured |
| LMArena Text: software and IT | Not measured | 1471 | Only Grok 4.5 measured |
| LMArena WebDev: React | 1657 | 1556 | GPT-6.1 Terra |
| LMArena WebDev: HTML | 1719 | 1568 | GPT-6.1 Terra |
| LMArena WebDev: from an image | Not measured | 1562 | Only Grok 4.5 measured |
| SciCode | Not measured | 6.5% | Only Grok 4.5 measured |
| Neither model has a result on the other 19 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| AA Intelligence Index | 51.0 | Not measured | Only GPT-6.1 Terra measured |
| Epoch Capabilities Index | Not measured | 154.1 | Only Grok 4.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 41.2 | Only Grok 4.5 measured |
| Design Arena: agents building web apps | Not measured | 1218 | Only Grok 4.5 measured |
| Design Arena: agents building full-stack apps | Not measured | 1249 | Only Grok 4.5 measured |
| Design Arena: agents building mobile apps | Not measured | 1216 | Only Grok 4.5 measured |
| Design Arena: agents building Android apps | Not measured | 1233 | Only Grok 4.5 measured |
| Design Arena: agents building Godot games | Not measured | 1229 | Only Grok 4.5 measured |
| Design Arena: agents building games | Not measured | 1200 | Only Grok 4.5 measured |
| Design Arena: HTML slides | Not measured | 1101 | Only Grok 4.5 measured |
| Design Arena: PowerPoint slides | Not measured | 1186 | Only Grok 4.5 measured |
| Design Arena: spreadsheets | Not measured | 1086 | Only Grok 4.5 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 |
| SREBench (Vals AI) | Not measured | 0.8% | Only Grok 4.5 measured |
| Finance Agent (Vals AI) | Not measured | 48.4% | Only Grok 4.5 measured |
| Tax Agent Bench (Vals AI) | 15.2% | 24.9% | Grok 4.5 |
| Legal Research Bench (Vals AI) | 26.0% | 38.0% | Grok 4.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 1.7% | Not measured | Only GPT-6.1 Terra measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 52.9% | Only Grok 4.5 measured |
| Time Horizon Index (Vals AI) | Not measured | 6.3% | Only Grok 4.5 measured |
| APEX-Agents | 68.3% | 56.2% | GPT-6.1 Terra |
| PostTrainBench | Not measured | 23.4% | Only Grok 4.5 measured |
| Vending-Bench 2 | Not measured | $3,887 | Only Grok 4.5 measured |
| LMArena Search | Not measured | 1216 | Only Grok 4.5 measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 92.9% | Only Grok 4.5 measured |
| LiveBench reasoning | 88.7% | Not measured | Only GPT-6.1 Terra measured |
| MMMU Pro (Vals AI) | Not measured | 61.8% | Only Grok 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 93.1% | Only Grok 4.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 46.2% | 42.7% | GPT-6.1 Terra |
| GPQA Diamond (Epoch AI run) | 94.3% | 93.4% | GPT-6.1 Terra |
| ARC-AGI | Not measured | 87.2% | Only Grok 4.5 measured |
| ARC-AGI-2 | Not measured | 52.6% | Only Grok 4.5 measured |
| SimpleBench | Not measured | 70.0% | Only Grok 4.5 measured |
| Chess puzzles | Not measured | 35.0% | Only Grok 4.5 measured |
| Mystery game puzzles | 74.0% | Not measured | Only GPT-6.1 Terra measured |
| EBR-bench | 78.1% | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text: hard prompts | Not measured | 1462 | Only Grok 4.5 measured |
| LMArena Text: expert | Not measured | 1465 | Only Grok 4.5 measured |
| LMArena Text: hard prompts in English | Not measured | 1464 | Only Grok 4.5 measured |
| LMArena Vision: diagrams | Not measured | 1304 | Only Grok 4.5 measured |
| LMArena Vision: homework | Not measured | 1295 | Only Grok 4.5 measured |
| Kagi LLM Benchmark | Not measured | 83.5% | Only Grok 4.5 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 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | 97.8% | GPT-6.1 Terra |
| FrontierMath, tiers 1 to 3 | 90.9% | 57.2% | GPT-6.1 Terra |
| FrontierMath, tier 4 | 92.7% | 24.4% | GPT-6.1 Terra |
| ProofBench | Not measured | 31.0% | Only Grok 4.5 measured |
| LMArena Text: math | Not measured | 1459 | Only Grok 4.5 measured |
| LMArena Text: mathematical work | Not measured | 1482 | Only Grok 4.5 measured |
| MathArena | Not measured | 34.1% | Only Grok 4.5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 89.2% | Only Grok 4.5 measured |
| LegalBench (Vals AI) | Not measured | 86.0% | Only Grok 4.5 measured |
| CorpFin (Vals AI) | Not measured | 67.4% | Only Grok 4.5 measured |
| TaxEval (Vals AI) | Not measured | 71.7% | Only Grok 4.5 measured |
| MortgageTax (Vals AI) | Not measured | 61.8% | Only Grok 4.5 measured |
| MedCode (Vals AI) | Not measured | 43.3% | Only Grok 4.5 measured |
| SimpleQA Verified | 57.3% | 48.3% | GPT-6.1 Terra |
| LMArena Text: science | Not measured | 1465 | Only Grok 4.5 measured |
| LMArena Text: medicine and healthcare | Not measured | 1440 | Only Grok 4.5 measured |
| LMArena Text: legal and government | Not measured | 1463 | Only Grok 4.5 measured |
| LMArena Text: business and finance | Not measured | 1441 | Only Grok 4.5 measured |
| FACTS Benchmark Suite | Not measured | 40.6% | Only Grok 4.5 measured |
| Neither model has a result on the other 8 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| Design Arena: websites | 1283 | 1280 | GPT-6.1 Terra |
| Design Arena: UI components | 1277 | 1274 | GPT-6.1 Terra |
| Design Arena: game dev | 1348 | 1262 | GPT-6.1 Terra |
| Design Arena: data viz | Not measured | 1268 | Only Grok 4.5 measured |
| Design Arena: 3D | Not measured | 1254 | Only Grok 4.5 measured |
| Design Arena: all code categories | 1295 | 1274 | GPT-6.1 Terra |
| Design Arena: SVG | Not measured | 1209 | Only Grok 4.5 measured |
| Design Arena: ASCII art | Not measured | 1256 | Only Grok 4.5 measured |
| LiveBench design | 82.3% | Not measured | Only GPT-6.1 Terra measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-6.1 Terra | Grok 4.5 | Leader |
|---|---|---|---|
| Vals Index | 60.5% | Not measured | Only GPT-6.1 Terra measured |
| LiveBench data analysis | 82.3% | Not measured | Only GPT-6.1 Terra measured |
| MedScribe (Vals AI) | Not measured | 86.9% | Only Grok 4.5 measured |
| Vals Multimodal Index | Not measured | 63.4% | Only Grok 4.5 measured |
| Long context reasoning (AA-LCR) | 82.7% | 79.3% | GPT-6.1 Terra |
| DTBench | Not measured | 96.5% | Only Grok 4.5 measured |
| LMCA | Not measured | 45.2% | Only Grok 4.5 measured |
| Surface Evolver Bench | Not measured | 74.4% | Only Grok 4.5 measured |
| Furniture assembly | 79.2% | 22.5% | GPT-6.1 Terra |
| LMArena Text | Not measured | 1448 | Only Grok 4.5 measured |
| LMArena Text: instruction following | Not measured | 1445 | Only Grok 4.5 measured |
| LMArena Text: creative writing | Not measured | 1442 | Only Grok 4.5 measured |
| LMArena Vision | Not measured | 1287 | Only Grok 4.5 measured |
| LMArena Text: English | Not measured | 1453 | Only Grok 4.5 measured |
| LMArena Text: non-English | Not measured | 1440 | Only Grok 4.5 measured |
| LMArena Text: Chinese | Not measured | 1494 | Only Grok 4.5 measured |
| LMArena Text: German | Not measured | 1446 | Only Grok 4.5 measured |
| LMArena Text: Japanese | Not measured | 1429 | Only Grok 4.5 measured |
| LMArena Text: Korean | Not measured | 1403 | Only Grok 4.5 measured |
| LMArena Text: French | Not measured | 1457 | Only Grok 4.5 measured |
| LMArena Text: Spanish | Not measured | 1451 | Only Grok 4.5 measured |
| LMArena Text: Russian | Not measured | 1450 | Only Grok 4.5 measured |
| LMArena Text: Polish | Not measured | 1431 | Only Grok 4.5 measured |
| LMArena Text: multi-turn | Not measured | 1456 | Only Grok 4.5 measured |
| LMArena Text: longer queries | Not measured | 1462 | Only Grok 4.5 measured |
| LMArena Text: writing and language | Not measured | 1445 | Only Grok 4.5 measured |
| LMArena Text: entertainment and media | Not measured | 1433 | Only Grok 4.5 measured |
| LMArena Vision: English | Not measured | 1285 | Only Grok 4.5 measured |
| LMArena Vision: Chinese | Not measured | 1345 | Only Grok 4.5 measured |
| LMArena Vision: reading text | Not measured | 1293 | Only Grok 4.5 measured |
| LMArena Vision: humor | Not measured | 1276 | Only Grok 4.5 measured |
| LMArena Vision: creative writing | Not measured | 1293 | Only Grok 4.5 measured |
| LMArena Document | Not measured | 1452 | Only Grok 4.5 measured |
| MultiChallenge | 74.2% | Not measured | Only GPT-6.1 Terra measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-6.1 Terra | Grok 4.5 | 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
GPT-6.1 Terra costs less
Repository review
50K input + 3K output tokens
GPT-6.1 Terra costs less
Agent loop
200K input + 10K output tokens
GPT-6.1 Terra 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 | SpaceXAI Grok 4.5 |
|---|---|---|
| Maker | OpenAI | xAI |
| Weights | No public weights listed | No public weights listed |
| Released | October 26, 2026 | July 8, 2026 |
| Context window | 1.05M | 500K |
| Input $/Mtok | $1.00 | $2.00 |
| Output $/Mtok | $5.00 | $6.00 |
| Coding index | 77.4 | 52.3 |
| Independent measurements behind it | 4 | 5 |
| Cost per solved task | Not computable | $0.62 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6.1 Terra better than Grok 4.5 for coding?
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 52.3 for Grok 4.5, though on 4 benchmarks against 5. Pick Grok 4.5 for work measured by Tax Agent Bench (Vals AI) or Legal Research Bench (Vals AI), where it leads.
Which is cheaper, GPT-6.1 Terra or Grok 4.5?
GPT-6.1 Terra costs $1.00 per million input tokens and $5.00 per million output tokens; Grok 4.5 costs $2.00 and $6.00. Cost per solved task is known for Grok 4.5 only.
Which has the bigger context window, GPT-6.1 Terra or Grok 4.5?
GPT-6.1 Terra, with 1.05M tokens against 500K.
How many benchmarks is the GPT-6.1 Terra vs Grok 4.5 comparison based on?
22 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 Grok 4.5's on 5. Where only one model has a result, the page says so instead of naming a winner.