LLMBenchmark.ai

Enter opens the highlighted result. Esc closes.

Claude Opus 4.5 vs GPT-5.6 Terra

Updated October 21, 2026. 82 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace Claude Opus 4.5 Replace GPT-5.6 Terra
Claude Opus 4.5Anthropic
Coding
66.8
Overall
29.1
Output $/M
$25.00
33
GPT-5.6 TerraOpenAI
Coding
69.0
Overall
42.1
Output $/M
$12.00
49
vs boards won of 82 shared

Decision reading

Pick GPT-5.6 Terra for coding: it scores 69.0 on the Vibe Coding Index against 66.8 for Claude Opus 4.5.

Pick Claude Opus 4.5 when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.

Model AClaude Opus 4.5Anthropic66.8/1002 independent benchmarks$1.37 per solved taskModel BGPT-5.6 TerraOpenAI69.0/1002 independent benchmarks$0.42 per solved task
Shared results
82
Claude Opus 4.5 only
23
GPT-5.6 Terra only
42
Like-for-like categories
8 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

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.

At a glance

Coding index
Claude Opus 4.5 66.8 from 2 benchmarks, GPT-5.6 Terra 69.0 from 2 benchmarks.
Widest category
Math, 28.5 points apart on average over 6 shared benchmarks.
Widest single gap
FrontierMath, tier 4: Claude Opus 4.5 4.9% against GPT-5.6 Terra 70.7%, 65.9 points apart on a 0 to 100 scale.
Output price
Claude Opus 4.5 $25.00 against GPT-5.6 Terra $12.00 per million output tokens, 2.1x apart.
Context window
Claude Opus 4.5 takes 200K tokens, GPT-5.6 Terra 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.

Boards won, where both have a result
CategoryClaude Opus 4.5BarsGPT-5.6 TerraTies
Coding28
Intelligence02
Agentic work52
Reasoning310
Math06
Knowledge74
Web design44
General1213
All shared boards3349
CodingLike-for-likeFour of these boards feed the Vibe Coding Index28
Coding benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
SWE-bench Verified79.2%Not measuredOnly Claude Opus 4.5 measured
SWE-bench (full test set)52.6%Not measuredOnly Claude Opus 4.5 measured
SWE-bench Multilingual70.7%Not measuredOnly Claude Opus 4.5 measured
LiveBench codingNot measured86.2%Only GPT-5.6 Terra measured
LMArena WebDev14941522GPT-5.6 Terra
AA Coding IndexNot measured76.7Only GPT-5.6 Terra measured
LiveCodeBench (Vals AI)83.7%85.9%GPT-5.6 Terra
SWE-bench Verified (Vals AI)76.4%95.4%GPT-5.6 Terra
Terminal-Bench 4 (Vals AI)Not measured22.7%Only GPT-5.6 Terra measured
Vibe Code Bench (Vals AI)20.6%74.6%GPT-5.6 Terra
Code migration (Vals AI)Not measured47.8%Only GPT-5.6 Terra measured
ProgramBench (Vals AI)Not measured0.5%Only GPT-5.6 Terra measured
IOI (Vals AI)Not measured87.6%Only GPT-5.6 Terra measured
Terminal-Bench 2.1 (Vals AI)Not measured77.5%Only GPT-5.6 Terra measured
Vibe Code Bench 1-100 (Vals AI)Not measured14.8%Only GPT-5.6 Terra measured
SkillsBench (Vals AI)Not measured58.9%Only GPT-5.6 Terra measured
CyberBench (Vals AI)Not measured72.1%Only GPT-5.6 Terra measured
LiveCodeBench (Artificial Analysis run)87.1%Not measuredOnly Claude Opus 4.5 measured
SciCodeNot measured55.0%Only GPT-5.6 Terra measured
Terminal-Bench Hard (Artificial Analysis run)47.0%62.9%GPT-5.6 Terra
Terminal-Bench63.1%Not measuredOnly Claude Opus 4.5 measured
FrontierCodeNot measured41.3%Only GPT-5.6 Terra measured
GSO-Bench26.5%Not measuredOnly Claude Opus 4.5 measured
WeirdML63.7%78.3%GPT-5.6 Terra
Cybench82.0%Not measuredOnly Claude Opus 4.5 measured
ALE-BenchNot measured1951.4Only GPT-5.6 Terra measured
LMArena Text: coding15031485Claude Opus 4.5
LMArena Text: software and IT14831482Claude Opus 4.5
LMArena WebDev: React14781513GPT-5.6 Terra
LMArena WebDev: HTML15101526GPT-5.6 Terra
LMArena WebDev: from an imageNot measured1541Only GPT-5.6 Terra measured
Neither model has a result on the other 7 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
Intelligence benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
AA Intelligence Index29.142.1GPT-5.6 Terra
Epoch Capabilities Index150.1160.1GPT-5.6 Terra
Agentic workLike-for-likePublic boards, shown as published, kept out of the index52
Agentic work benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
AA Agentic IndexNot measured43.2Only GPT-5.6 Terra measured
Design Arena: agents building web apps11591120Claude Opus 4.5
Design Arena: agents building full-stack apps11561061Claude Opus 4.5
Design Arena: agents building mobile apps11891112Claude Opus 4.5
Design Arena: agents building Android apps11811066Claude Opus 4.5
Design Arena: agents building gamesNot measured1082Only GPT-5.6 Terra measured
Design Arena: HTML slidesNot measured1108Only GPT-5.6 Terra measured
Design Arena: PowerPoint slidesNot measured1130Only GPT-5.6 Terra measured
LiveBench researchNot measured60.4%Only GPT-5.6 Terra measured
LiveBench browserNot measured84.0%Only GPT-5.6 Terra measured
LiveBench long agenticNot measured48.4%Only GPT-5.6 Terra measured
SREBench (Vals AI)Not measured9.5%Only GPT-5.6 Terra measured
Finance Agent (Vals AI)Not measured54.4%Only GPT-5.6 Terra measured
Tax Agent Bench (Vals AI)Not measured30.0%Only GPT-5.6 Terra measured
Legal Research Bench (Vals AI)Not measured41.4%Only GPT-5.6 Terra measured
Excel Modeling Benchmark (Vals AI)Not measured66.2%Only GPT-5.6 Terra measured
Terminal-Bench-Science (Vals AI)Not measured10.0%Only GPT-5.6 Terra measured
τ²-Bench Telecom89.5%86.3%Claude Opus 4.5
APEX-AgentsNot measured58.2%Only GPT-5.6 Terra measured
METR time horizons75.0%Not measuredOnly Claude Opus 4.5 measured
Remote Labor Index3.8%Not measuredOnly Claude Opus 4.5 measured
GDPval45.5%Not measuredOnly Claude Opus 4.5 measured
BALROG43.5%53.2%GPT-5.6 Terra
DeepResearch Bench54.8%Not measuredOnly Claude Opus 4.5 measured
OSWorld66.3%Not measuredOnly Claude Opus 4.5 measured
Vending-Bench 2$4,967$7,343GPT-5.6 Terra
Neither model has a result on the other 13 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index310
Reasoning benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
GPQA Diamond85.9%90.9%GPT-5.6 Terra
LiveBench reasoningNot measured90.6%Only GPT-5.6 Terra measured
MMMU Pro (Vals AI)83.0%86.5%GPT-5.6 Terra
GPQA Diamond (Artificial Analysis run)86.6%92.5%GPT-5.6 Terra
Humanity's Last Exam (Artificial Analysis run)30.1%42.9%GPT-5.6 Terra
GPQA Diamond (Epoch AI run)86.0%93.3%GPT-5.6 Terra
ARC-AGI80.0%96.5%GPT-5.6 Terra
ARC-AGI-237.6%83.9%GPT-5.6 Terra
SimpleBench62.0%48.9%Claude Opus 4.5
Chess puzzles14.0%47.0%GPT-5.6 Terra
Mystery game puzzles22.0%35.0%GPT-5.6 Terra
EBR-bench14.3%Not measuredOnly Claude Opus 4.5 measured
VPCT40.0%Not measuredOnly Claude Opus 4.5 measured
LMArena Text: hard prompts14761469Claude Opus 4.5
LMArena Text: expert14871496GPT-5.6 Terra
LMArena Text: hard prompts in English14821465Claude Opus 4.5
LMArena Vision: diagramsNot measured1295Only GPT-5.6 Terra measured
LMArena Vision: homeworkNot measured1312Only GPT-5.6 Terra measured
Neither model has a result on the other 3 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index06
Math benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
AIME95.4%Not measuredOnly Claude Opus 4.5 measured
MGSM (Vals AI)95.2%Not measuredOnly Claude Opus 4.5 measured
AA Math Index91.3Not measuredOnly Claude Opus 4.5 measured
AIME 2025 (Artificial Analysis run)91.3%Not measuredOnly Claude Opus 4.5 measured
OTIS Mock AIME86.1%99.7%GPT-5.6 Terra
FrontierMath, tiers 1 to 334.4%86.0%GPT-5.6 Terra
FrontierMath, tier 44.9%70.7%GPT-5.6 Terra
ProofBench36.0%74.0%GPT-5.6 Terra
LMArena Text: math14631465GPT-5.6 Terra
LMArena Text: mathematical work14681478GPT-5.6 Terra
Neither model has a result on the other 3 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index74
Knowledge benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
MMLU Pro87.3%86.7%Claude Opus 4.5
LegalBench (Vals AI)84.6%85.1%GPT-5.6 Terra
CaseLaw (Vals AI)62.6%Not measuredOnly Claude Opus 4.5 measured
CorpFin (Vals AI)65.1%65.3%GPT-5.6 Terra
TaxEval (Vals AI)74.9%76.2%GPT-5.6 Terra
MortgageTax (Vals AI)68.7%67.3%Claude Opus 4.5
MedQA (Vals AI)95.9%Not measuredOnly Claude Opus 4.5 measured
MedCode (Vals AI)49.2%43.4%Claude Opus 4.5
MMLU Pro (Artificial Analysis run)89.5%Not measuredOnly Claude Opus 4.5 measured
SimpleQA Verified45.7%43.2%Claude Opus 4.5
GeoBench75.0%Not measuredOnly Claude Opus 4.5 measured
LMArena Text: science14541452Claude Opus 4.5
LMArena Text: medicine and healthcare14441430Claude Opus 4.5
LMArena Text: legal and government14591461GPT-5.6 Terra
LMArena Text: business and finance14481448Claude Opus 4.5
Neither model has a result on the other 2 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index44
Web design benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
Design Arena: websites12471269GPT-5.6 Terra
Design Arena: UI components12381259GPT-5.6 Terra
Design Arena: game dev12291230GPT-5.6 Terra
Design Arena: data viz12431240Claude Opus 4.5
Design Arena: 3D12141135Claude Opus 4.5
Design Arena: all code categories12421241Claude Opus 4.5
Design Arena: SVG11801220GPT-5.6 Terra
Design Arena: ASCII art11901177Claude Opus 4.5
LiveBench designNot measured76.0%Only GPT-5.6 Terra measured
GeneralLike-for-likePublic boards, shown as published, kept out of the index1213
General benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
LiveBench data analysisNot measured79.3%Only GPT-5.6 Terra measured
Public Benefits Bench (Vals AI)Not measured62.4%Only GPT-5.6 Terra measured
SAGE (Vals AI)52.1%47.0%Claude Opus 4.5
MedScribe (Vals AI)85.3%82.9%Claude Opus 4.5
Vals Multimodal IndexNot measured65.1%Only GPT-5.6 Terra measured
IFBench58.0%71.2%GPT-5.6 Terra
Long context reasoning (AA-LCR)77.3%83.0%GPT-5.6 Terra
DTBench89.9%93.3%GPT-5.6 Terra
LMCA44.5%54.9%GPT-5.6 Terra
CL-bench21.1%Not measuredOnly Claude Opus 4.5 measured
Surface Evolver BenchNot measured83.8%Only GPT-5.6 Terra measured
Furniture assembly28.3%54.2%GPT-5.6 Terra
LMArena Text14511448Claude Opus 4.5
LMArena Text: instruction following14781456Claude Opus 4.5
LMArena Text: creative writing14451413Claude Opus 4.5
LMArena VisionNot measured1271Only GPT-5.6 Terra measured
LMArena Text: English14611449Claude Opus 4.5
LMArena Text: non-English14381441GPT-5.6 Terra
LMArena Text: Chinese14701514GPT-5.6 Terra
LMArena Text: German14491460GPT-5.6 Terra
LMArena Text: Japanese14171454GPT-5.6 Terra
LMArena Text: Korean14241427GPT-5.6 Terra
LMArena Text: French14711466Claude Opus 4.5
LMArena Text: Spanish14571451Claude Opus 4.5
LMArena Text: Russian14471452GPT-5.6 Terra
LMArena Text: Polish14391446GPT-5.6 Terra
LMArena Text: multi-turn14661453Claude Opus 4.5
LMArena Text: longer queries14791454Claude Opus 4.5
LMArena Text: writing and language14521431Claude Opus 4.5
LMArena Text: entertainment and media14341418Claude Opus 4.5
LMArena Vision: EnglishNot measured1272Only GPT-5.6 Terra measured
LMArena Vision: ChineseNot measured1337Only GPT-5.6 Terra measured
LMArena Vision: reading textNot measured1278Only GPT-5.6 Terra measured
LMArena Vision: humorNot measured1236Only GPT-5.6 Terra measured
LMArena Vision: creative writingNot measured1248Only GPT-5.6 Terra measured
LMArena Document14621472GPT-5.6 Terra
Neither model has a result on the other 10 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Opus 4.5 and GPT-5.6 Terra
BenchmarkClaude Opus 4.5GPT-5.6 TerraLeader
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

Claude Opus 4.5$0.018Fits in one request
GPT-5.6 Terra$0.0080Fits in one request

GPT-5.6 Terra costs less

Repository review

50K input + 3K output tokens

Claude Opus 4.5$0.325Fits in one request
GPT-5.6 Terra$0.136Fits in one request

GPT-5.6 Terra costs less

Agent loop

200K input + 10K output tokens

Claude Opus 4.5$1.25Exceeds the context window
GPT-5.6 Terra$0.520Fits in one request

GPT-5.6 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.

Specifications of Claude Opus 4.5 and GPT-5.6 Terra
SpecificationAnthropic Claude Opus 4.5OpenAI GPT-5.6 Terra
MakerAnthropicOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedNovember 24, 2025July 9, 2026
Context window200K1.05M
Input $/Mtok$5.00$2.00
Output $/Mtok$25.00$12.00
Coding index66.869.0
Independent measurements behind it22
Cost per solved task$1.37$0.42
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Opus 4.5 better than GPT-5.6 Terra for coding?

Pick GPT-5.6 Terra for coding: it scores 69.0 on the Vibe Coding Index against 66.8 for Claude Opus 4.5. Pick Claude Opus 4.5 when what matters is LMArena Text: coding or LMArena Text: software and IT, where it leads.

Which is cheaper, Claude Opus 4.5 or GPT-5.6 Terra?

Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; GPT-5.6 Terra costs $2.00 and $12.00. Per solved SWE-bench Verified task, Claude Opus 4.5 costs $1.37 and GPT-5.6 Terra $0.42.

Which has the bigger context window, Claude Opus 4.5 or GPT-5.6 Terra?

GPT-5.6 Terra, with 1.05M tokens against 200K.

How many benchmarks is the Claude Opus 4.5 vs GPT-5.6 Terra comparison based on?

82 benchmarks have a result for both models as of October 21, 2026. Claude Opus 4.5's coding index rests on 2 independent benchmarks and GPT-5.6 Terra's on 2. Where only one model has a result, the page says so instead of naming a winner.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/claude-opus-4-5-vs-gpt-5-6-terra" title="Claude Opus 4.5 vs GPT-5.6 Terra, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/claude-opus-4-5-vs-gpt-5-6-terra">LLMBenchmark.ai, Claude Opus 4.5 vs GPT-5.6 Terra</a></p>