Enter opens the highlighted result. Esc closes.

Claude Sonnet 5.5 vs GPT-5.5

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 Sonnet 5.5 Replace GPT-5.5
Claude Sonnet 5.5Anthropic
Coding
88.9
Overall
56.0
Output $/M
$10.00
64
GPT-5.5OpenAI
Coding
67.8
Overall
38.4
Output $/M
$30.00
18
vs boards won of 82 shared

Decision reading

Pick Claude Sonnet 5.5 for coding: it scores 88.9 on the Vibe Coding Index against 67.8 for GPT-5.5.

Pick GPT-5.5 when the context window is larger, 1.05M against 1M tokens, or when what matters is ALE-Bench or Chess puzzles, where it leads.

Model AClaude Sonnet 5.5Anthropic88.9/1002 independent benchmarksNo cost per solved taskModel BGPT-5.5OpenAI67.8/1002 independent benchmarks$1.65 per solved task
Shared results
82
Claude Sonnet 5.5 only
13
GPT-5.5 only
50
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 Sonnet 5.5 88.9 from 2 benchmarks, GPT-5.5 67.8 from 2 benchmarks.
Widest category
Agentic work, 20.5 points apart on average over 12 shared benchmarks.
Widest single gap
ProofBench: Claude Sonnet 5.5 100.0% against GPT-5.5 50.0%, 50.0 points apart on a 0 to 100 scale.
Output price
Claude Sonnet 5.5 $10.00 against GPT-5.5 $30.00 per million output tokens, 3.0x apart.
Context window
Claude Sonnet 5.5 takes 1M tokens, GPT-5.5 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 Sonnet 5.5BarsGPT-5.5Ties
Coding131
Intelligence20
Agentic work120
Reasoning82
Math60
Knowledge15
Web design70
General1510
All shared boards6418
CodingLike-for-likeFour of these boards feed the Vibe Coding Index131
Coding benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
LiveBench coding94.7%85.1%Claude Sonnet 5.5
LMArena WebDev17681513Claude Sonnet 5.5
AA Coding IndexNot measured74.9Only GPT-5.5 measured
LiveCodeBench (Vals AI)Not measured85.3%Only GPT-5.5 measured
SWE-bench Verified (Vals AI)Not measured82.6%Only GPT-5.5 measured
Terminal-Bench 4 (Vals AI)64.1%Not measuredOnly Claude Sonnet 5.5 measured
Vibe Code Bench (Vals AI)92.4%69.8%Claude Sonnet 5.5
Code migration (Vals AI)69.8%45.2%Claude Sonnet 5.5
ProgramBench (Vals AI)6.5%0.5%Claude Sonnet 5.5
IOI (Vals AI)83.1%Not measuredOnly Claude Sonnet 5.5 measured
Terminal-Bench 2.1 (Vals AI)83.2%76.4%Claude Sonnet 5.5
SWE-bench Multimodal (Vals AI)58.3%Not measuredOnly Claude Sonnet 5.5 measured
SkillsBench (Vals AI)Not measured62.5%Only GPT-5.5 measured
CyberBench (Vals AI)59.6%Not measuredOnly Claude Sonnet 5.5 measured
SciCode61.0%56.1%Claude Sonnet 5.5
Terminal-Bench Hard (Artificial Analysis run)Not measured60.6%Only GPT-5.5 measured
Terminal-BenchNot measured84.7%Only GPT-5.5 measured
FrontierCode52.1%43.0%Claude Sonnet 5.5
FrontierSWE61.9%Not measuredOnly Claude Sonnet 5.5 measured
GSO-BenchNot measured40.2%Only GPT-5.5 measured
WeirdMLNot measured84.9%Only GPT-5.5 measured
MirrorCodeNot measured10.0%Only GPT-5.5 measured
ALE-Bench1819.11943.0GPT-5.5
LMArena Text: coding15131494Claude Sonnet 5.5
LMArena Text: software and IT15041493Claude Sonnet 5.5
LMArena WebDev: React18171506Claude Sonnet 5.5
LMArena WebDev: HTML17411543Claude Sonnet 5.5
LMArena WebDev: from an image17371532Claude Sonnet 5.5
Neither model has a result on the other 10 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
AA Intelligence Index56.038.4Claude Sonnet 5.5
Epoch Capabilities Index166.2159.7Claude Sonnet 5.5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index120
Agentic work benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
AA Agentic IndexNot measured36.4Only GPT-5.5 measured
Design Arena: agents building web apps13031117Claude Sonnet 5.5
Design Arena: agents building full-stack appsNot measured1089Only GPT-5.5 measured
Design Arena: agents building mobile apps12651143Claude Sonnet 5.5
Design Arena: agents building Android appsNot measured1169Only GPT-5.5 measured
Design Arena: agents building Godot gamesNot measured1173Only GPT-5.5 measured
Design Arena: agents building gamesNot measured1179Only GPT-5.5 measured
Design Arena: HTML slidesNot measured1067Only GPT-5.5 measured
Design Arena: PowerPoint slidesNot measured1108Only GPT-5.5 measured
Design Arena: spreadsheets1245Not measuredOnly Claude Sonnet 5.5 measured
LiveBench research83.6%61.6%Claude Sonnet 5.5
LiveBench browser84.0%48.0%Claude Sonnet 5.5
LiveBench long agentic78.8%44.6%Claude Sonnet 5.5
SREBench (Vals AI)30.1%3.8%Claude Sonnet 5.5
Finance Agent (Vals AI)58.1%51.8%Claude Sonnet 5.5
Tax Agent Bench (Vals AI)42.0%21.8%Claude Sonnet 5.5
Legal Research Bench (Vals AI)48.1%40.4%Claude Sonnet 5.5
Harvey's Legal Agent Benchmark (Vals AI)10.4%Not measuredOnly Claude Sonnet 5.5 measured
Excel Modeling Benchmark (Vals AI)75.7%64.5%Claude Sonnet 5.5
BioMysteryBench (Vals AI)81.1%Not measuredOnly Claude Sonnet 5.5 measured
Terminal-Bench-Science (Vals AI)47.1%Not measuredOnly Claude Sonnet 5.5 measured
Vals Science Index59.1%Not measuredOnly Claude Sonnet 5.5 measured
Time Horizon Index (Vals AI)Not measured8.3%Only GPT-5.5 measured
τ²-Bench TelecomNot measured93.9%Only GPT-5.5 measured
APEX-Agents75.5%55.1%Claude Sonnet 5.5
Remote Labor IndexNot measured6.3%Only GPT-5.5 measured
OSWorld 2.0Not measured13.0%Only GPT-5.5 measured
DeepResearch BenchNot measured54.0%Only GPT-5.5 measured
PostTrainBenchNot measured27.2%Only GPT-5.5 measured
SpireClimb1.3%Not measuredOnly Claude Sonnet 5.5 measured
Vending-Bench 2$11,165$7,524Claude Sonnet 5.5
Neither model has a result on the other 8 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index82
Reasoning benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
GPQA DiamondNot measured93.2%Only GPT-5.5 measured
LiveBench reasoning91.6%89.7%Claude Sonnet 5.5
MysteryMechanism (Vals AI)49.1%Not measuredOnly Claude Sonnet 5.5 measured
MMMU Pro (Vals AI)Not measured88.3%Only GPT-5.5 measured
GPQA Diamond (Artificial Analysis run)Not measured93.5%Only GPT-5.5 measured
Humanity's Last Exam (Artificial Analysis run)55.0%45.8%Claude Sonnet 5.5
GPQA Diamond (Epoch AI run)95.6%90.7%Claude Sonnet 5.5
ARC-AGINot measured95.0%Only GPT-5.5 measured
ARC-AGI-2Not measured85.0%Only GPT-5.5 measured
SimpleBenchNot measured69.0%Only GPT-5.5 measured
Chess puzzles59.0%63.0%GPT-5.5
Mystery game puzzles65.0%56.0%Claude Sonnet 5.5
EBR-benchNot measured34.3%Only GPT-5.5 measured
LMArena Text: hard prompts14941489Claude Sonnet 5.5
LMArena Text: expert15311507Claude Sonnet 5.5
LMArena Text: hard prompts in English15021483Claude Sonnet 5.5
LMArena Vision: diagrams13291325Claude Sonnet 5.5
LMArena Vision: homework13311332GPT-5.5
Neither model has a result on the other 3 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index60
Math benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
OTIS Mock AIME100.0%84.4%Claude Sonnet 5.5
FrontierMath, tiers 1 to 388.8%85.3%Claude Sonnet 5.5
FrontierMath, tier 480.5%72.5%Claude Sonnet 5.5
ProofBench100.0%50.0%Claude Sonnet 5.5
LMArena Text: math14971487Claude Sonnet 5.5
LMArena Text: mathematical work15101496Claude Sonnet 5.5
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index15
Knowledge benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
MMLU ProNot measured88.1%Only GPT-5.5 measured
LegalBench (Vals AI)Not measured86.5%Only GPT-5.5 measured
CaseLaw (Vals AI)Not measured66.2%Only GPT-5.5 measured
CorpFin (Vals AI)Not measured68.4%Only GPT-5.5 measured
TaxEval (Vals AI)Not measured75.0%Only GPT-5.5 measured
MortgageTax (Vals AI)Not measured68.8%Only GPT-5.5 measured
MedCode (Vals AI)52.9%49.1%Claude Sonnet 5.5
SimpleQA Verified46.5%63.0%GPT-5.5
LMArena Text: science14831485GPT-5.5
LMArena Text: medicine and healthcare14641465GPT-5.5
LMArena Text: legal and government14831491GPT-5.5
LMArena Text: business and finance14681478GPT-5.5
Neither model has a result on the other 5 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index70
Web design benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
Design Arena: websites13261256Claude Sonnet 5.5
Design Arena: UI components13671260Claude Sonnet 5.5
Design Arena: game dev14691294Claude Sonnet 5.5
Design Arena: data viz13891265Claude Sonnet 5.5
Design Arena: 3D14581198Claude Sonnet 5.5
Design Arena: all code categories13641260Claude Sonnet 5.5
Design Arena: SVGNot measured1234Only GPT-5.5 measured
Design Arena: ASCII artNot measured1254Only GPT-5.5 measured
LiveBench design85.0%70.3%Claude Sonnet 5.5
GeneralLike-for-likePublic boards, shown as published, kept out of the index1510
General benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
Vals Index70.8%Not measuredOnly Claude Sonnet 5.5 measured
LiveBench data analysis59.5%81.6%GPT-5.5
Public Benefits Bench (Vals AI)67.2%60.9%Claude Sonnet 5.5
SAGE (Vals AI)51.8%51.5%Claude Sonnet 5.5
MedScribe (Vals AI)91.1%86.9%Claude Sonnet 5.5
Vals Multimodal IndexNot measured68.1%Only GPT-5.5 measured
IFBenchNot measured75.9%Only GPT-5.5 measured
Long context reasoning (AA-LCR)82.7%84.3%GPT-5.5
DTBench97.3%96.0%Claude Sonnet 5.5
LMCA68.3%54.3%Claude Sonnet 5.5
Surface Evolver BenchNot measured88.1%Only GPT-5.5 measured
Furniture assembly75.0%44.2%Claude Sonnet 5.5
ExploitBenchNot measured47.4%Only GPT-5.5 measured
CL-bench LifeNot measured22.2%Only GPT-5.5 measured
LMArena Text14731471Claude Sonnet 5.5
LMArena Text: instruction following14921478Claude Sonnet 5.5
LMArena Text: creative writing14671455Claude Sonnet 5.5
LMArena Vision12871297GPT-5.5
LMArena Text: English14841470Claude Sonnet 5.5
LMArena Text: non-English14561467GPT-5.5
LMArena Text: Chinese15351534Claude Sonnet 5.5
LMArena Text: GermanNot measured1480Only GPT-5.5 measured
LMArena Text: JapaneseNot measured1499Only GPT-5.5 measured
LMArena Text: KoreanNot measured1460Only GPT-5.5 measured
LMArena Text: French14991485Claude Sonnet 5.5
LMArena Text: Spanish14511468GPT-5.5
LMArena Text: Russian14541473GPT-5.5
LMArena Text: PolishNot measured1465Only GPT-5.5 measured
LMArena Text: multi-turn14651476GPT-5.5
LMArena Text: longer queries14951484Claude Sonnet 5.5
LMArena Text: writing and language14741466Claude Sonnet 5.5
LMArena Text: entertainment and media14611449Claude Sonnet 5.5
LMArena Vision: English12891292GPT-5.5
LMArena Vision: ChineseNot measured1360Only GPT-5.5 measured
LMArena Vision: reading text12971306GPT-5.5
LMArena Vision: humorNot measured1293Only GPT-5.5 measured
LMArena Vision: recognizing thingsNot measured1231Only GPT-5.5 measured
LMArena Vision: creative writing12421301GPT-5.5
LMArena DocumentNot measured1486Only GPT-5.5 measured
Neither model has a result on the other 7 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Sonnet 5.5 and GPT-5.5
BenchmarkClaude Sonnet 5.5GPT-5.5Leader
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 Sonnet 5.5$0.0070Fits in one request
GPT-5.5$0.020Fits in one request

Claude Sonnet 5.5 costs less

Repository review

50K input + 3K output tokens

Claude Sonnet 5.5$0.130Fits in one request
GPT-5.5$0.340Fits in one request

Claude Sonnet 5.5 costs less

Agent loop

200K input + 10K output tokens

Claude Sonnet 5.5$0.500Fits in one request
GPT-5.5$1.30Fits in one request

Claude Sonnet 5.5 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 Sonnet 5.5 and GPT-5.5
SpecificationAnthropic Claude Sonnet 5.5OpenAI GPT-5.5
MakerAnthropicOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedSeptember 28, 2026April 24, 2026
Context window1M1.05M
Input $/Mtok$2.00$5.00
Output $/Mtok$10.00$30.00
Coding index88.967.8
Independent measurements behind it22
Cost per solved taskNot computable$1.65
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Sonnet 5.5 better than GPT-5.5 for coding?

Pick Claude Sonnet 5.5 for coding: it scores 88.9 on the Vibe Coding Index against 67.8 for GPT-5.5. Pick GPT-5.5 when the context window is larger, 1.05M against 1M tokens, or when what matters is ALE-Bench or Chess puzzles, where it leads.

Which is cheaper, Claude Sonnet 5.5 or GPT-5.5?

Claude Sonnet 5.5 costs $2.00 per million input tokens and $10.00 per million output tokens; GPT-5.5 costs $5.00 and $30.00. Cost per solved task is known for GPT-5.5 only.

Which has the bigger context window, Claude Sonnet 5.5 or GPT-5.5?

GPT-5.5, with 1.05M tokens against 1M.

How many benchmarks is the Claude Sonnet 5.5 vs GPT-5.5 comparison based on?

82 benchmarks have a result for both models as of October 21, 2026. Claude Sonnet 5.5's coding index rests on 2 independent benchmarks and GPT-5.5'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-sonnet-5-5-vs-gpt-5-5" title="Claude Sonnet 5.5 vs GPT-5.5, 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-sonnet-5-5-vs-gpt-5-5">LLMBenchmark.ai, Claude Sonnet 5.5 vs GPT-5.5</a></p>