BenchLeader

Gemini 4 Carbon vs GPT-5.6 Terra

Full profiles: Gemini 4 Carbon (Google) and GPT-5.6 Terra (OpenAI): every benchmark, price and rank.

Updated · Data from 8 sources

As of 29 Oct 2026, Gemini 4 Carbon and GPT-5.6 Terra are neck and neck on quality (65.1 vs 61.1 on the BenchLeader Index, inside the ±7.9 margin), and GPT-5.6 Terra is 1.8× cheaper at $4.50 vs $8.00 per 1M tokens blended. Choose Gemini 4 Carbon for knowledge (76 vs 48), reasoning (79 vs 61), and coding (72 vs 65); choose GPT-5.6 Terra for long context (66 vs 65), where it also streams faster.

Key facts (as of 29 Oct 2026)

  • Gemini 4 Carbon scores 65.1 on the BenchLeader Index and GPT-5.6 Terra scores 61.1 (BenchLeader, 29 Oct 2026).
  • Gemini 4 Carbon costs $8.00 per 1M tokens blended (list price, 29 Oct 2026).
  • GPT-5.6 Terra costs $4.50 per 1M tokens blended (list price, 29 Oct 2026).
  • GPT-5.6 Terra streams faster than Gemini 4 Carbon (Artificial Analysis, 7-day median, 29 Oct 2026).
  • Of the 17 benchmarks both models have, Gemini 4 Carbon leads 16 (BenchLeader, 29 Oct 2026).

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
CodingGemini 4 Carbon72 vs 65 category score; SciCode 64.2% vs 55.0%Medium
ReasoningGemini 4 Carbon79 vs 61 category score; HLE-Diamond (AA) 69.1% vs 28.8%High
KnowledgeGemini 4 Carbon76 vs 48 category score; AA-Omniscience v1.1 53.5 vs -9.3High
Long documentsGPT-5.6 Terra66 vs 65 category score; AA-LCR v1.1 83.0% vs 79.3%Medium
Lowest costGPT-5.6 Terra$4.50 vs $8.00 per 1M blended; agentic coding session $0.168 vs $0.320–
Fastest first answerEither103.1 s (Gemini 4 Carbon (high)) vs 107.1 s (GPT-5.6 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

  • Gemini 4 Carbon (high) and GPT-5.6 Terra (max) are neck and neck on quality (65.1 vs 61.1, within the ±7.9 margin).
  • Gemini 4 Carbon (high) is stronger in coding, knowledge, reasoning.
  • GPT-5.6 Terra (max) is stronger in long context, agents & tools, instruction following, maths, multimodal.
  • GPT-5.6 Terra (max) is 1.8× cheaper ($4.50 vs $8.00 per 1M blended).
  • GPT-5.6 Terra (max) streams 1.4× faster (139 vs 100 tokens per second).

At a glance

SpecGemini 4 CarbonGPT-5.6 Terra
DeveloperGoogleOpenAI
Released28 Oct 20269 Jul 2026
Context window (tokens)1,000,0001,050,000
Compared atGemini 4 Carbon (high)GPT-5.6 Terra (max)
Open weightsNoNo
Price in / out / cached input per 1M$4.00 / $20.00 / –$2.00 / $12.00 / $0.200

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.

CategoryGemini 4 Carbon (high)GPT-5.6 Terra (max)Leader
Reasoning78.961.3Gemini 4 Carbon
Coding71.764.9Gemini 4 Carbon
Agents & tools–58.8not comparable
Maths–68.6not comparable
Knowledge75.848.2Gemini 4 Carbon
Instruction following–69.9not comparable
Multimodal–63.4not comparable
Long context64.566.4GPT-5.6 Terra

Where sources disagree

Across the 17 benchmarks both have, Gemini 4 Carbon leads 16, GPT-5.6 Terra leads 1.

Overall indexGemini 4 Carbon (high)GPT-5.6 Terra (max)Leader
BenchLeader Index65.161.1neck and neck

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.

MeasureGemini 4 Carbon (high)GPT-5.6 Terra (max)
Blended price per 1M tokens$8.00$4.50
Input / output per 1M$4.00 / $20.00$2.00 / $12.00
Cached input per 1M–$0.200
Price per task: chat reply$0.0076$0.0044
Price per task: summarize a 30-page report$0.060$0.031
Price per task: code edit$0.054$0.030
Price per task: agentic coding session$0.320$0.168
Price per task: structured extraction$0.012$0.0064
Cost to run a full benchmark suite$7.76–
Output speed100 tok/s139 tok/s
Time to first answer103.1 s107.1 s
Time to a complete answer108.1 s110.7 s

Each model is compared at its best-ranked reasoning-effort setting. Gemini 4 Carbon (high) scores 65.1 and takes 103 s to its first answer token. GPT-5.6 Terra (max) scores 61.1 and takes 107 s to its first answer token; GPT-5.6 Terra (xhigh) scores 60.4 in 8 s, GPT-5.6 Terra (high) scores 56.9 in 2 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

125 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.

MetricPublisherGemini 4 Carbon (high)GPT-5.6 Terra (max)
BenchLeader IndexBenchLeader65.161.1
Coding scoreBenchLeader71.764.9
Knowledge scoreBenchLeader75.848.2
Long context scoreBenchLeader64.566.4
Reasoning scoreBenchLeader78.961.3
Agents & tools scoreBenchLeader–58.8
Instruction following scoreBenchLeader–69.9
Maths scoreBenchLeader–68.6
Multimodal scoreBenchLeader–63.4
Blended price $/MBenchLeader$8.00$4.50
Output speedBenchLeader100 tok/s139 tok/s
Time to first answerBenchLeader103.1 s107.1 s
Context windowBenchLeader1,000,000 tokens1,050,000 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub–93.3%
SimpleBenchSimpleBench–48.9%†
Arena Hard PromptsArena (LMArena)–1490†
LiveBench 2.0 ReasoningLiveBench–90.6%†
LiveBench 1.0 ReasoningLiveBench–90.6%
GPQA Diamond (AA)Artificial Analysis–92.5%
Humanity's Last Exam (AA)Artificial Analysis60.4%42.9%
HLE-Diamond (AA)Artificial Analysis69.1%28.8%
GPQA Diamond (Vals)Vals AI–90.9%†
Kagi LLM BenchmarkKagi LLM Benchmark–51.3%†
ARC-AGI-1ARC Prize–96.5%
ARC-AGI-2ARC Prize–83.9%
ARC-AGI-3ARC Prize–0.8%
CritPtArtificial Analysis36.0%30.0%
CritPt v2 hard subset (AA)Artificial Analysis63.0%–
Chess PuzzlesEpoch AI Benchmarking Hub–47.0%
Mystery Game PuzzlesEpoch AI Benchmarking Hub–35.0%
LMCAEpoch AI Benchmarking Hub–55.0%
DTBenchEpoch AI Benchmarking Hub–93.3%
Coding
SciCodeSciCode64.2%55.0%
WeirdMLWeirdML–78.3%†
FrontierCodeCognition–41.3%†
Arena CodingArena (LMArena)–1518†
Arena WebDevArena (LMArena)–1520†
LiveBench 2.0 CodingLiveBench–86.2%†
Show all 125 benchmarks
MetricPublisherGemini 4 Carbon (high)GPT-5.6 Terra (max)
Coding
LiveBench 1.0 CodingLiveBench–78.3%
LiveCodeBenchVals AI–85.9%†
IOIVals AI–87.6%
SWE-bench (Vals)Vals AI–95.4%
Code MigrationVals AI–47.8%
ProgramBenchVals AI–0.5%
Vibe Code Bench 1-100Vals AI–14.8%
Vibe Code Bench v1.1Vals AI89.1%74.6%
Surface Evolver BenchEpoch AI Benchmarking Hub–83.8%†
DeepSWE v1.1Epoch AI Benchmarking Hub–69.6%
CursorBenchCursor–41.3%
ALE-BenchEpoch AI Benchmarking Hub–1951.4
Terminal-Bench 4.0 (AA)Artificial Analysis65.2%35.4%
Terminal-Bench 2.1 (AA)Artificial Analysis–88.0%
Startrise FrontendStartrise–66.9%†
FrontierCode 1.1 (AA)Artificial Analysis48.5%–
FrontierCode 2.0 (AA)Artificial Analysis40.6%–
Agents & tools
Terminal-BenchTerminal-Bench–21.5%
APEX-AgentsMercor–58.2%
Arena AgentArena (LMArena)–0.2†
LiveBench Long AgenticLiveBench–33.1%†
LiveBench BrowserLiveBench–70.3%†
LiveBench Agentic CodingLiveBench–55.0%
Terminal-Bench HardArtificial Analysis–57.6%
τ²-Bench Telecom (AA)Artificial Analysis–86.3%
Terminal-Bench 2.1 (Vals)Vals AI–77.5%
GDPval-AA v2.1Artificial Analysis–47.6%
τ³-Banking (AA)Artificial Analysis–40.2%
ITBench SRE (AA)Artificial Analysis–51.0%
APEX-Agents (AA)Artificial Analysis–38.9%
CyberBenchVals AI–72.1%
Finance Agent v2Vals AI–54.4%
Finance Agent v2.1Vals AI67.2%–
Harvey's Legal Agent Benchmark v1.1Vals AI17.5%–
Harvey's Legal Agent Benchmark v1Vals AI–0.8%
Legal Research BenchVals AI55.8%41.4%
SkillsBenchVals AI–58.9%
SREBenchVals AI–9.5%
Tax Agent BenchVals AI48.9%30.0%
Terminal-Bench 4.0 (Vals)Vals AI63.1%22.7%
Terminal-Bench ScienceVals AI–10.0%
BALROGBALROG–53.2%
Vending-Bench 2Andon Labs16484.2†7343.2†
AutomationBenchArtificial Analysis77.8%59.6%
GDP.pdf (AA)Artificial Analysis28.4%24.0%
EnterpriseOps-GymArtificial Analysis–38.5%
AA-Briefcase v1.1Artificial Analysis1609–
Terminal-Bench-Science 0.1 (AA)Artificial Analysis64.8%13.8%
FACTS SearchGoogle–81.7%†
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub–86.0%
FrontierMath Tier 4Epoch AI Benchmarking Hub–70.7%
OTIS Mock AIMEEpoch AI Benchmarking Hub–99.7%
ProofBenchVals AI–74.0%†
LiveBench MathematicsLiveBench–94.9%
Arena MathsArena (LMArena)–1483†
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub–43.2%
LiveBench 2.0 Data AnalysisLiveBench–79.3%†
LiveBench ResearchLiveBench–60.4%†
LiveBench 1.0 Data AnalysisLiveBench–79.3%
AA-Omniscience v1.1Artificial Analysis53.5-9.3
MMLU-ProVals AI–86.7%†
LegalBenchVals AI–85.1%
CorpFinVals AI–65.3%†
TaxEvalVals AI–76.2%†
Excel Modeling BenchmarkVals AI–66.2%
Excel Modeling Benchmark v1.1Vals AI76.5%–
MedCodeVals AI–43.4%†
MedScribeVals AI–82.9%†
Public Benefits Bench v1.1Vals AI–62.4%
GDP.pdfEpoch AI Benchmarking Hub–24.7%†
AA-Omniscience v1.1: accuracyArtificial Analysis58.3%42.3%
AA-Omniscience v1.1: non-hallucinationArtificial Analysis88.6%10.6%
Instruction following
LiveBench LanguageLiveBench–82.9%
LiveBench Instruction FollowingLiveBench–64.6%
IFBenchArtificial Analysis–71.2%
Arena Instruction FollowingArena (LMArena)–1464†
Human preference
Arena TextArena (LMArena)–1467†
EQ-Bench 4EQ-Bench–1220†
Arena Creative WritingArena (LMArena)–1429†
Arena Multi-turnArena (LMArena)–1472†
Arena Longer QueriesArena (LMArena)–1468†
Multimodal
Arena VisionArena (LMArena)–1271†
LiveBench DesignLiveBench–76.0%†
MMMU-ProArtificial Analysis–80.7%
MMMU-Pro (Vals)Vals AI–86.5%
MortgageTaxVals AI–67.3%†
SAGEVals AI–87.0%
Blueprint-Bench 2Epoch AI Benchmarking Hub58.6%†30.8%†
Long context
AA-LCR v1.1Artificial Analysis79.3%83.0%
Arena DocumentArena (LMArena)–1477†
MLCRArtificial Analysis–27.2%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub–160.1†
LiveBench 2.0LiveBench–67.8%†
LiveBench 1.0LiveBench–77.9%
AA Intelligence Index v5.0Artificial Analysis59.4–
AA Intelligence Index v4.3.2Artificial Analysis–42.1
AA Progress Index v1Artificial Analysis351.6323.9
Vals IndexVals AI70.4–
Vals Finance IndexVals AI66.3%–
Vals Multimodal IndexVals AI–65.1%†

Data as of 2026-10-29. Best configuration of each model; every score links to its source on the model pages.

What changed

  • GPT-5.6 Terra (max): BenchLeader Index 62.5 → 61.2.
  • GPT-5.6 Terra (max): 2 new results (AA Progress Index v1, HLE-Diamond (AA)); 4 score revisions.
  • 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): 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 63.4 → 62.5.
  • GPT-5.6 Terra (max): 1 new result (Public Benefits Bench v1.1); 2 score revisions.

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

Gemini 4 Carbon vs GPT-5.6 Terra: questions

Is Gemini 4 Carbon better than GPT-5.6 Terra?
Gemini 4 Carbon (high) and GPT-5.6 Terra (max) are neck and neck on quality (65.1 vs 61.1, within the ±7.9 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 29 Oct 2026, so check the category scores for your use.
Gemini 4 Carbon vs GPT-5.6 Terra: which is cheaper, and will that change?
GPT-5.6 Terra is cheaper today: $4.50 against $8.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is Gemini 4 Carbon or GPT-5.6 Terra better for coding?
Gemini 4 Carbon scores higher in coding (72 vs 65 on the category index, where 50 is average). On SciCode, the top shared coding benchmark, it is 64.2% for Gemini 4 Carbon against 55.0% for GPT-5.6 Terra.
Which is faster, Gemini 4 Carbon or GPT-5.6 Terra?
GPT-5.6 Terra streams faster (139 vs 100 output tokens per second, Artificial Analysis 7-day median).
Which is better for long documents?
GPT-5.6 Terra scores higher on long-context benchmarks (66 vs 65). Both take about 1.1M tokens: Gemini 4 Carbon 1,000,000, GPT-5.6 Terra 1,050,000.
More questions (3)
Which has lower latency?
Gemini 4 Carbon answers first: 103.1 s against 107.1 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.
Do independent benchmarks agree on Gemini 4 Carbon vs GPT-5.6 Terra?
Across the 17 benchmarks both have, Gemini 4 Carbon leads 16, GPT-5.6 Terra leads 1.
When was Gemini 4 Carbon released?
Gemini 4 Carbon was released on 28 Oct 2026.