BenchLeader

GPT-5.6 Terra vs GPT-6.1 Terra

Full profiles: GPT-5.6 Terra (OpenAI) and GPT-6.1 Terra (OpenAI): every benchmark, price and rank.

Updated · Data from 8 sources

As of 27 Oct 2026, GPT-5.6 Terra (max) and GPT-6.1 Terra (max) are neck and neck on quality (64.2 vs 65.9 on the BenchLeader Index, inside the ±8.6 margin of error), and GPT-6.1 Terra (max) costs 2.3× less, which makes it the better buy for most workloads. GPT-6.1 Terra leads in every category we measure both in.

Which to pick for…

The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.

Use casePickWhyConfidence
ReasoningGPT-6.1 Terra86 vs 70 category score; CritPt 28.0% vs 30.0%High
KnowledgeGPT-6.1 Terra75 vs 57 category score; AA-Omniscience 29.8 vs 0.1High
Long documentsEither67 vs 66 category score; AA-LCR 83.0% vs 82.7%Either
Images and other mediaGPT-6.1 Terra68 vs 63 category score; MMMU-Pro 84.7% vs 80.7%Medium
Lowest costGPT-6.1 Terra$2.00 vs $4.50 per 1M blended; agentic coding session $0.080 vs $0.168–
Fastest first answerEither111.8 s (GPT-5.6 Terra (max)) vs 131.8 s (GPT-6.1 Terra (max)) to the first answer token–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • GPT-5.6 Terra (max) and GPT-6.1 Terra (max) are neck and neck on quality (64.2 vs 65.9, within the ±8.6 margin).
  • GPT-5.6 Terra (max) is stronger in agents & tools, coding, instruction following, long context, maths.
  • GPT-6.1 Terra (max) is stronger in composite, knowledge, multimodal, reasoning.
  • GPT-6.1 Terra (max) is 2.3× cheaper ($2.00 vs $4.50 per 1M blended).
  • GPT-5.6 Terra (max) streams 1.5× faster (135 vs 91 tokens per second).

At a glance

SpecGPT-5.6 TerraGPT-6.1 Terra
DeveloperOpenAIOpenAI
Released9 Jul 202626 Oct 2026
Context window (tokens)1,050,0001,050,000
Compared atGPT-5.6 Terra (max)GPT-6.1 Terra (max)
Open weightsNoNo
Price in / out / cached input per 1M$2.00 / $12.00 / $0.200$1.00 / $5.00 / $0.050

Category by category

Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.

CategoryGPT-5.6 Terra (max)GPT-6.1 Terra (max)Leader
Reasoning70.086.2GPT-6.1 Terra
Coding64.9–not comparable
Agents & tools58.9–not comparable
Maths68.9–not comparable
Knowledge57.074.5GPT-6.1 Terra
Instruction following69.9–not comparable
Multimodal63.467.5GPT-6.1 Terra
Long context66.566.3level
Composite76.182.8GPT-6.1 Terra

Where sources disagree

Across the 12 benchmarks both have, GPT-5.6 Terra leads 2, GPT-6.1 Terra leads 10. Every overall index that rates both puts GPT-6.1 Terra ahead.

Overall indexGPT-5.6 Terra (max)GPT-6.1 Terra (max)Leader
BenchLeader Index64.265.9neck and neck
AA Intelligence Index v4.3.242.148.1GPT-6.1 Terra

Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).

Price, speed and latency

List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.

MeasureGPT-5.6 Terra (max)GPT-6.1 Terra (max)
Blended price per 1M tokens$4.50$2.00
Input / output per 1M$2.00 / $12.00$1.00 / $5.00
Cached input per 1M$0.200$0.050
Price per task: chat reply$0.0044$0.0019
Price per task: summarize a 30-page report$0.031$0.015
Price per task: code edit$0.030$0.013
Price per task: agentic coding session$0.168$0.080
Price per task: structured extraction$0.0064$0.0030
Cost to run a full benchmark suite$1.40$0.403
Output speed135 tok/s91 tok/s
Time to first answer111.8 s131.8 s
Time to a complete answer115.4 s137.3 s

Per token is not per task: on Artificial Analysis' full suite GPT-5.6 Terra (max) cost $1.40 and GPT-6.1 Terra (max) $0.403, because GPT-5.6 Terra (max) used about 1.5× as many tokens for the same work, which a per-token price hides.

Each model is compared at its best-ranked reasoning-effort setting. GPT-5.6 Terra (max) scores 64.2 and takes 112 s to its first answer token; GPT-5.6 Terra (xhigh) scores 62.7 in 30 s, GPT-5.6 Terra (high) scores 61.2 in 3 s. GPT-6.1 Terra (max) scores 65.9 and takes 132 s to its first answer token; GPT-6.1 Terra (xhigh) scores 65.0 in 18 s, GPT-6.1 Terra (high) scores 64.7 in 7 s. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.

Every benchmark

117 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.

MetricPublisherGPT-5.6 Terra (max)GPT-6.1 Terra (max)
BenchLeader IndexBenchLeader64.265.9
Agents & tools scoreBenchLeader58.9–
Coding scoreBenchLeader64.9–
Composite scoreBenchLeader76.182.8
Instruction following scoreBenchLeader69.9–
Knowledge scoreBenchLeader57.074.5
Long context scoreBenchLeader66.566.3
Maths scoreBenchLeader68.9–
Multimodal scoreBenchLeader63.467.5
Reasoning scoreBenchLeader70.086.2
Blended price $/MBenchLeader$4.50$2.00
Output speedBenchLeader135 tok/s91 tok/s
Time to first answerBenchLeader111.8 s131.8 s
Context windowBenchLeader1,050,000 tokens1,050,000 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub93.3%–
SimpleBenchSimpleBench48.9%†–
Arena Hard PromptsArena (LMArena)1490†–
LiveBench 2.0 ReasoningLiveBench90.6%†88.7%†
LiveBench 1.0 ReasoningLiveBench90.6%–
GPQA Diamond (AA)Artificial Analysis92.5%–
Humanity's Last Exam (AA)Artificial Analysis42.9%46.3%
GPQA Diamond (Vals)Vals AI90.9%†–
Kagi LLM BenchmarkKagi LLM Benchmark51.3%†–
ARC-AGI-1ARC Prize96.5%–
ARC-AGI-2ARC Prize83.9%–
ARC-AGI-3ARC Prize0.8%–
CritPtArtificial Analysis30.0%28.0%
Chess PuzzlesEpoch AI Benchmarking Hub47.0%–
Mystery Game PuzzlesEpoch AI Benchmarking Hub35.0%–
LMCAEpoch AI Benchmarking Hub55.0%–
DTBenchEpoch AI Benchmarking Hub93.3%–
Coding
SciCodeSciCode55.0%–
WeirdMLWeirdML78.3%†–
FrontierCodeCognition41.3%†–
Arena CodingArena (LMArena)1518†–
Arena WebDevArena (LMArena)1521†–
LiveBench 2.0 CodingLiveBench86.2%†90.8%†
LiveBench 1.0 CodingLiveBench78.3%–
SciCode (AA)Artificial Analysis55.0%55.1%
Show all 117 benchmarks
MetricPublisherGPT-5.6 Terra (max)GPT-6.1 Terra (max)
Coding
LiveCodeBenchVals AI85.9%†–
IOIVals AI87.6%–
SWE-bench (Vals)Vals AI95.4%–
Code MigrationVals AI47.8%–
ProgramBenchVals AI0.5%–
Vibe Code Bench 1-100Vals AI14.8%–
Vibe Code Bench v1.1Vals AI74.6%–
Surface Evolver BenchEpoch AI Benchmarking Hub83.8%†–
DeepSWE v1.1Epoch AI Benchmarking Hub69.6%–
CursorBenchCursor41.3%–
ALE-BenchEpoch AI Benchmarking Hub1951.4–
Terminal-Bench 4.0 (AA)Artificial Analysis35.4%55.6%
Terminal-Bench 2.1 (AA)Artificial Analysis88.0%–
Startrise FrontendStartrise66.9%†–
FrontierCode 1.1 (AA)Artificial Analysis–36.0%
Agents & tools
Terminal-BenchTerminal-Bench21.5%–
APEX-AgentsMercor58.2%–
Arena AgentArena (LMArena)0.2†–
LiveBench Long AgenticLiveBench33.1%†48.6%†
LiveBench BrowserLiveBench70.3%†93.1%†
LiveBench Agentic CodingLiveBench55.0%–
Terminal-Bench HardArtificial Analysis57.6%–
τ²-Bench Telecom (AA)Artificial Analysis86.3%–
Terminal-Bench 2.1 (Vals)Vals AI77.5%–
GDPval-AA v2.1Artificial Analysis47.6%–
τ³-Banking (AA)Artificial Analysis40.2%–
ITBench SRE (AA)Artificial Analysis51.0%–
APEX-Agents (AA)Artificial Analysis38.9%–
CyberBenchVals AI72.1%–
Finance Agent v2Vals AI54.4%–
Harvey's Legal Agent Benchmark v1Vals AI0.8%–
Legal Research BenchVals AI41.4%–
SkillsBenchVals AI58.9%–
SREBenchVals AI9.5%–
Tax Agent BenchVals AI30.0%–
Terminal-Bench 4.0 (Vals)Vals AI22.7%–
Terminal-Bench ScienceVals AI10.0%–
BALROGBALROG53.2%–
Vending-Bench 2Andon Labs7343.2†–
AutomationBenchArtificial Analysis59.6%60.2%
GDP.pdf (AA)Artificial Analysis24.0%28.6%
EnterpriseOps-GymArtificial Analysis38.5%–
AA-Briefcase v1.1Artificial Analysis–1402
Terminal-Bench-Science 0.1 (AA)Artificial Analysis13.8%57.6%
FACTS SearchGoogle81.7%†–
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub86.0%–
FrontierMath Tier 4Epoch AI Benchmarking Hub70.7%–
OTIS Mock AIMEEpoch AI Benchmarking Hub99.7%–
ProofBenchVals AI74.0%†–
LiveBench MathematicsLiveBench94.9%–
Arena MathsArena (LMArena)1483†–
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub43.2%–
LiveBench 2.0 Data AnalysisLiveBench79.3%†82.3%†
LiveBench ResearchLiveBench60.4%†73.9%†
LiveBench 1.0 Data AnalysisLiveBench79.3%–
AA-OmniscienceArtificial Analysis0.129.8
MMLU-ProVals AI86.7%†–
LegalBenchVals AI85.1%–
CorpFinVals AI65.3%†–
TaxEvalVals AI76.2%†–
Excel Modeling BenchmarkVals AI66.2%–
MedCodeVals AI43.4%†–
MedScribeVals AI82.9%†–
Public Benefits Bench v1.1Vals AI62.4%–
GDP.pdfEpoch AI Benchmarking Hub24.7%†–
AA-Omniscience: accuracyArtificial Analysis46.8%49.1%
AA-Omniscience: non-hallucinationArtificial Analysis12.1%62.0%
Instruction following
LiveBench LanguageLiveBench82.9%–
LiveBench Instruction FollowingLiveBench64.6%–
IFBenchArtificial Analysis71.2%–
Arena Instruction FollowingArena (LMArena)1464†–
Human preference
Arena TextArena (LMArena)1467†–
EQ-Bench 4EQ-Bench1224†–
Arena Creative WritingArena (LMArena)1429†–
Arena Multi-turnArena (LMArena)1472†–
Arena Longer QueriesArena (LMArena)1468†–
Multimodal
Arena VisionArena (LMArena)1271†–
LiveBench DesignLiveBench76.0%†82.3%†
MMMU-ProArtificial Analysis80.7%84.7%
MMMU-Pro (Vals)Vals AI86.5%–
MortgageTaxVals AI67.3%†–
SAGEVals AI47.0%–
Blueprint-Bench 2Epoch AI Benchmarking Hub30.8%†–
Long context
AA-LCRArtificial Analysis83.0%82.7%
Arena DocumentArena (LMArena)1477†–
MLCRArtificial Analysis27.2%–
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub160.1†–
LiveBench 2.0LiveBench67.8%†77.2%†
LiveBench 1.0LiveBench77.9%–
AA Intelligence Index v4.3.2Artificial Analysis42.148.1
Vals Multimodal IndexVals AI65.1%†–
Safety & honesty
FORTRESSScale AI SEAL–18.2%†

Data as of 2026-10-27. Best configuration of each model; every score links to its source on the model pages.

What changed

  • GPT-5.6 Terra (max): 1 new result (Harvey's Legal Agent Benchmark v1).
  • GPT-5.6 Terra (max): 1 score revision.
  • GPT-5.6 Terra (max): BenchLeader Index 63.8 → 64.4.
  • GPT-5.6 Terra (max): 5 new results (AutomationBench, GDP.pdf (AA), MLCR…).
  • GPT-5.6 Terra (max): 1 new result (SREBench); 1 score revision.
  • GPT-5.6 Terra (max): 1 score revision.
  • GPT-5.6 Terra (max): 1 score revision.
  • GPT-5.6 Terra (max): BenchLeader Index 64.5 → 63.8.
  • GPT-5.6 Terra (max): 1 new result (Public Benefits Bench v1.1); 2 score revisions.
  • GPT-5.6 Terra (max): 1 new result (CyberBench).

Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs

GPT-5.6 Terra vs GPT-6.1 Terra: questions

Is GPT-5.6 Terra better than GPT-6.1 Terra?
GPT-5.6 Terra (max) and GPT-6.1 Terra (max) are neck and neck on quality (64.2 vs 65.9, within the ±8.6 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 2026-10-27, so check the category scores for your use.
Which is cheaper, GPT-5.6 Terra or GPT-6.1 Terra, and will that change?
GPT-6.1 Terra is cheaper today: $2.00 against $4.50 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Which is better for long documents?
They are level on long-context benchmarks (67 vs 66). Both accept 1,050,000 tokens of context.
Which has lower latency?
GPT-5.6 Terra (max) answers first: 111.8 s against 131.8 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
Which is faster, GPT-5.6 Terra or GPT-6.1 Terra?
GPT-5.6 Terra streams faster: 135 against 91 output tokens per second.
Do independent benchmarks agree on GPT-5.6 Terra vs GPT-6.1 Terra?
Across the 12 benchmarks both have, GPT-5.6 Terra leads 2, GPT-6.1 Terra leads 10. Every overall index that rates both puts GPT-6.1 Terra ahead.
When was GPT-6.1 Terra released?
GPT-6.1 Terra was released on 26 Oct 2026.