GPT-6.1 Terra vs Muse Spark 1.2
GPT-6.1 Terra leads Muse Spark 1.2 on coding, 77.4 to 50.9 on the Vibe Coding Index, at about the same output price ($5.00 vs $4.25 per million). Updated October 29, 2026; 16 benchmarks have a result for both.
GPT-6.1 Terra or Muse Spark 1.2: which to pick
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 50.9 for Muse Spark 1.2.
Pick Muse Spark 1.2 for output tokens 1.2x cheaper ($4.25 vs $5.00 per million) and work measured by SciCode or Tax Agent Bench (Vals AI), where it leads.
- Shared results
- 16
- GPT-6.1 Terra only
- 20
- Muse Spark 1.2 only
- 75
- Like-for-like categories
- 6 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 50.9.
4 benchmarks behind each score
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 Muse Spark 1.2 has a AA Agentic Index result, 43.2.
Directional only
Knowledge
MMLU Pro
No call
Only Muse Spark 1.2 has a MMLU Pro result, 88.3%.
Directional only
Web design
Design Arena: websites
Muse Spark 1.2
Muse Spark 1.2 leads, 1311 against 1283.
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 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Spark 1.2
GPT-6.1 Terra $0.0035, Muse Spark 1.2 $0.0034 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Muse Spark 1.2 has the number, $0.64.
Directional only
At a glance
- Coding index
- GPT-6.1 Terra 77.4 from 4 benchmarks, Muse Spark 1.2 50.9 from 4 benchmarks.
- Widest category
- Agentic work, 19.4 points apart on average over 3 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): GPT-6.1 Terra 49.5% against Muse Spark 1.2 6.1%, 57.9 points apart on a 0 to 100 scale.
- Output price
- GPT-6.1 Terra $5.00 against Muse Spark 1.2 $4.25 per million output tokens, 1.2x apart.
- Context window
- GPT-6.1 Terra takes 1.05M tokens, Muse Spark 1.2 1.05M.
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 | Muse Spark 1.2 | Ties |
|---|---|---|---|---|
| Coding | 5 | 1 | ||
| Agentic work | 1 | 2 | ||
| Reasoning | 1 | 0 | ||
| Knowledge | 0 | 1 | ||
| Web design | 1 | 3 | ||
| General | 1 | 0 | ||
| All shared boards | 9 | 7 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index51
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| LiveBench coding | 94.3% | Not measured | Only GPT-6.1 Terra measured |
| LMArena WebDev | 1673 | 1534 | GPT-6.1 Terra |
| AA Coding Index | Not measured | 72.2 | Only Muse Spark 1.2 measured |
| SWE-bench Verified (Vals AI) | Not measured | 86.6% | Only Muse Spark 1.2 measured |
| Terminal-Bench 4 (Vals AI) | 49.5% | 6.1% | GPT-6.1 Terra |
| Vibe Code Bench (Vals AI) | 84.0% | 79.1% | GPT-6.1 Terra |
| Code migration (Vals AI) | Not measured | 29.9% | Only Muse Spark 1.2 measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Muse Spark 1.2 measured |
| IOI (Vals AI) | Not measured | 21.8% | Only Muse Spark 1.2 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 69.7% | Only Muse Spark 1.2 measured |
| SkillsBench (Vals AI) | Not measured | 53.0% | Only Muse Spark 1.2 measured |
| CyberBench (Vals AI) | Not measured | 69.5% | Only Muse Spark 1.2 measured |
| SciCode | 55.1% | 57.4% | Muse Spark 1.2 |
| FrontierSWE | Not measured | 12.0% | Only Muse Spark 1.2 measured |
| WeirdML | Not measured | 60.3% | Only Muse Spark 1.2 measured |
| ALE-Bench | 2608.8 | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text: coding | Not measured | 1506 | Only Muse Spark 1.2 measured |
| LMArena Text: software and IT | Not measured | 1508 | Only Muse Spark 1.2 measured |
| LMArena WebDev: React | 1657 | 1526 | GPT-6.1 Terra |
| LMArena WebDev: HTML | 1719 | 1543 | GPT-6.1 Terra |
| Neither model has a result on the other 23 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| AA Intelligence Index | 51.0 | Not measured | Only GPT-6.1 Terra measured |
| Epoch Capabilities Index | Not measured | 155.1 | Only Muse Spark 1.2 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 43.2 | Only Muse Spark 1.2 measured |
| Design Arena: agents building web apps | Not measured | 1223 | Only Muse Spark 1.2 measured |
| Design Arena: agents building full-stack apps | Not measured | 1210 | Only Muse Spark 1.2 measured |
| Design Arena: agents building mobile apps | Not measured | 1184 | Only Muse Spark 1.2 measured |
| Design Arena: agents building Android apps | Not measured | 1220 | Only Muse Spark 1.2 measured |
| Design Arena: agents building games | Not measured | 1142 | Only Muse Spark 1.2 measured |
| Design Arena: HTML slides | Not measured | 1031 | Only Muse Spark 1.2 measured |
| Design Arena: PowerPoint slides | Not measured | 1149 | Only Muse Spark 1.2 measured |
| Design Arena: spreadsheets | Not measured | 1059 | Only Muse Spark 1.2 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 | 0.0% | Only Muse Spark 1.2 measured |
| Finance Agent (Vals AI) | Not measured | 60.6% | Only Muse Spark 1.2 measured |
| Tax Agent Bench (Vals AI) | 15.2% | 32.8% | Muse Spark 1.2 |
| Legal Research Bench (Vals AI) | 26.0% | 43.8% | Muse Spark 1.2 |
| Harvey's Legal Agent Benchmark (Vals AI) | 1.7% | Not measured | Only GPT-6.1 Terra measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 57.0% | Only Muse Spark 1.2 measured |
| BioMysteryBench (Vals AI) | Not measured | 64.8% | Only Muse Spark 1.2 measured |
| APEX-Agents | 68.3% | 45.4% | GPT-6.1 Terra |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| LiveBench reasoning | 88.7% | Not measured | Only GPT-6.1 Terra measured |
| MMMU Pro (Vals AI) | Not measured | 86.1% | Only Muse Spark 1.2 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 90.4% | Only Muse Spark 1.2 measured |
| Humanity's Last Exam (Artificial Analysis run) | 46.2% | 45.5% | GPT-6.1 Terra |
| GPQA Diamond (Epoch AI run) | 94.3% | Not measured | Only GPT-6.1 Terra measured |
| SimpleBench | Not measured | 74.5% | Only Muse Spark 1.2 measured |
| Chess puzzles | Not measured | 27.0% | Only Muse Spark 1.2 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 | 1492 | Only Muse Spark 1.2 measured |
| LMArena Text: expert | Not measured | 1477 | Only Muse Spark 1.2 measured |
| LMArena Text: hard prompts in English | Not measured | 1491 | Only Muse Spark 1.2 measured |
| LMArena Vision: diagrams | Not measured | 1317 | Only Muse Spark 1.2 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 9 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only GPT-6.1 Terra measured |
| FrontierMath, tiers 1 to 3 | 90.9% | Not measured | Only GPT-6.1 Terra measured |
| FrontierMath, tier 4 | 92.7% | Not measured | Only GPT-6.1 Terra measured |
| ProofBench | Not measured | 43.0% | Only Muse Spark 1.2 measured |
| LMArena Text: math | Not measured | 1485 | Only Muse Spark 1.2 measured |
| LMArena Text: mathematical work | Not measured | 1488 | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 8 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 88.3% | Only Muse Spark 1.2 measured |
| LegalBench (Vals AI) | Not measured | 85.3% | Only Muse Spark 1.2 measured |
| CorpFin (Vals AI) | Not measured | 70.9% | Only Muse Spark 1.2 measured |
| TaxEval (Vals AI) | Not measured | 80.4% | Only Muse Spark 1.2 measured |
| MortgageTax (Vals AI) | Not measured | 65.4% | Only Muse Spark 1.2 measured |
| MedCode (Vals AI) | Not measured | 49.4% | Only Muse Spark 1.2 measured |
| SimpleQA Verified | 57.3% | 60.3% | Muse Spark 1.2 |
| LMArena Text: science | Not measured | 1499 | Only Muse Spark 1.2 measured |
| LMArena Text: medicine and healthcare | Not measured | 1494 | Only Muse Spark 1.2 measured |
| LMArena Text: legal and government | Not measured | 1509 | Only Muse Spark 1.2 measured |
| LMArena Text: business and finance | Not measured | 1484 | Only Muse Spark 1.2 measured |
| Neither model has a result on the other 9 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index13
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | Leader |
|---|---|---|---|
| Design Arena: websites | 1283 | 1311 | Muse Spark 1.2 |
| Design Arena: UI components | 1277 | 1296 | Muse Spark 1.2 |
| Design Arena: game dev | 1348 | 1300 | GPT-6.1 Terra |
| Design Arena: data viz | Not measured | 1333 | Only Muse Spark 1.2 measured |
| Design Arena: 3D | Not measured | 1299 | Only Muse Spark 1.2 measured |
| Design Arena: all code categories | 1295 | 1311 | Muse Spark 1.2 |
| Design Arena: SVG | Not measured | 1280 | Only Muse Spark 1.2 measured |
| Design Arena: ASCII art | Not measured | 1279 | Only Muse Spark 1.2 measured |
| LiveBench design | 82.3% | Not measured | Only GPT-6.1 Terra measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | 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 |
| Public Benefits Bench (Vals AI) | Not measured | 68.5% | Only Muse Spark 1.2 measured |
| MedScribe (Vals AI) | Not measured | 90.1% | Only Muse Spark 1.2 measured |
| Vals Multimodal Index | Not measured | 69.8% | Only Muse Spark 1.2 measured |
| Long context reasoning (AA-LCR) | 82.7% | 79.0% | GPT-6.1 Terra |
| DTBench | Not measured | 94.7% | Only Muse Spark 1.2 measured |
| LMCA | Not measured | 48.4% | Only Muse Spark 1.2 measured |
| Furniture assembly | 79.2% | Not measured | Only GPT-6.1 Terra measured |
| LMArena Text | Not measured | 1483 | Only Muse Spark 1.2 measured |
| LMArena Text: instruction following | Not measured | 1465 | Only Muse Spark 1.2 measured |
| LMArena Text: creative writing | Not measured | 1437 | Only Muse Spark 1.2 measured |
| LMArena Vision | Not measured | 1304 | Only Muse Spark 1.2 measured |
| LMArena Text: English | Not measured | 1484 | Only Muse Spark 1.2 measured |
| LMArena Text: non-English | Not measured | 1475 | Only Muse Spark 1.2 measured |
| LMArena Text: Chinese | Not measured | 1510 | Only Muse Spark 1.2 measured |
| LMArena Text: German | Not measured | 1492 | Only Muse Spark 1.2 measured |
| LMArena Text: Japanese | Not measured | 1470 | Only Muse Spark 1.2 measured |
| LMArena Text: Korean | Not measured | 1454 | Only Muse Spark 1.2 measured |
| LMArena Text: French | Not measured | 1500 | Only Muse Spark 1.2 measured |
| LMArena Text: Spanish | Not measured | 1491 | Only Muse Spark 1.2 measured |
| LMArena Text: Russian | Not measured | 1481 | Only Muse Spark 1.2 measured |
| LMArena Text: multi-turn | Not measured | 1496 | Only Muse Spark 1.2 measured |
| LMArena Text: longer queries | Not measured | 1474 | Only Muse Spark 1.2 measured |
| LMArena Text: writing and language | Not measured | 1451 | Only Muse Spark 1.2 measured |
| LMArena Text: entertainment and media | Not measured | 1442 | Only Muse Spark 1.2 measured |
| LMArena Vision: English | Not measured | 1291 | Only Muse Spark 1.2 measured |
| LMArena Vision: reading text | Not measured | 1313 | Only Muse Spark 1.2 measured |
| MultiChallenge | 74.2% | Not measured | Only GPT-6.1 Terra measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-6.1 Terra | Muse Spark 1.2 | 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
Muse Spark 1.2 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 | Meta Muse Spark 1.2 |
|---|---|---|
| Maker | OpenAI | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | October 26, 2026 | August 5, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $1.00 | $1.25 |
| Output $/Mtok | $5.00 | $4.25 |
| Coding index | 77.4 | 50.9 |
| Independent measurements behind it | 4 | 4 |
| Cost per solved task | Not computable | $0.64 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6.1 Terra better than Muse Spark 1.2 for coding?
Pick GPT-6.1 Terra for coding: it scores 77.4 on the Vibe Coding Index against 50.9 for Muse Spark 1.2. Pick Muse Spark 1.2 for output tokens 1.2x cheaper ($4.25 vs $5.00 per million) and work measured by SciCode or Tax Agent Bench (Vals AI), where it leads.
Which is cheaper, GPT-6.1 Terra or Muse Spark 1.2?
GPT-6.1 Terra costs $1.00 per million input tokens and $5.00 per million output tokens; Muse Spark 1.2 costs $1.25 and $4.25. Cost per solved task is known for Muse Spark 1.2 only.
Which has the bigger context window, GPT-6.1 Terra or Muse Spark 1.2?
GPT-6.1 Terra, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-6.1 Terra vs Muse Spark 1.2 comparison based on?
16 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 Muse Spark 1.2's on 4. Where only one model has a result, the page says so instead of naming a winner.