BenchLeader

GPT-5.5 vs Step 5 Preview

Full profiles: GPT-5.5 (OpenAI) and Step 5 Preview (StepFun): every benchmark, price and rank.

Updated · Data from 12 sources

As of 13 Nov 2026, GPT-5.5 is ahead of Step 5 Preview on quality (64.1 vs 54.3 on the BenchLeader Index), but Step 5 Preview is 7.9× cheaper at $1.43 vs $11.25 per 1M tokens blended. Choose GPT-5.5 for reasoning (68 vs 52), agents & tools (62 vs 50), and coding (61 vs 50); choose Step 5 Preview for fast first answers (22.8 s vs 37.1 s) and long context (69 vs 67), where it also streams ~1.5× faster.

Key facts (as of 13 Nov 2026)

  • GPT-5.5 scores 64.1 on the BenchLeader Index and Step 5 Preview scores 54.3 (BenchLeader, 13 Nov 2026).
  • GPT-5.5 costs $11.25 per 1M tokens blended (list price, 13 Nov 2026).
  • Step 5 Preview costs $1.43 per 1M tokens blended (list price, 13 Nov 2026).
  • Step 5 Preview streams ~1.5× faster than GPT-5.5 (Artificial Analysis, 7-day median, 13 Nov 2026).
  • Of the 26 benchmarks both models have, GPT-5.5 leads 13 (BenchLeader, 13 Nov 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
CodingGPT-5.561 vs 50 category score; SciCode 55.8% vs 58.9%High
Agents & tool useGPT-5.562 vs 50 category score; Analyst Agent (AA) 50.0% vs 35.0%High
MathsGPT-5.570 vs 60 category score; ProofBench 50.0% vs 42.0%High
ReasoningGPT-5.568 vs 52 category score; CritPt 27.1% vs 20.9%High
KnowledgeGPT-5.564 vs 54 category score; Excel Modeling Benchmark 64.5% vs 57.1%High
Long documentsStep 5 Preview69 vs 67 category score; AA-LCR v1.1 88.3% vs 84.3%Medium
Images and other mediaGPT-5.562 vs 59 category score; MMMU-Pro 79.9% vs 76.4%Medium
Chat quality (human preference)–Only Step 5 Preview has an Arena rating (63 category score)Not comparable
Lowest costStep 5 Preview$1.43 vs $11.25 per 1M blended; agentic coding session $0.071 vs $0.420–
Fastest first answerStep 5 Preview22.8 s (Step 5 Preview) vs 37.1 s (GPT-5.5 (xhigh)) 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-5.5 (xhigh) leads on quality: 64.1 vs 54.3.
  • GPT-5.5 (xhigh) is stronger in agents & tools, coding, knowledge, maths, multimodal, reasoning.
  • Step 5 Preview is stronger in long context.
  • Step 5 Preview is 7.9× cheaper ($1.43 vs $11.25 per 1M blended).
  • Step 5 Preview streams 1.9× faster (135 vs 70 tokens per second).

At a glance

SpecGPT-5.5Step 5 Preview
DeveloperOpenAIStepFun
Released23 Apr 202618 Sep 2026
Context window (tokens)1,050,0001,000,000
Compared atGPT-5.5 (xhigh)Step 5 Preview
Open weightsNoYes
Price in / out / cached input per 1M$5.00 / $30.00 / $0.500$1.00 / $2.70 / $0.105

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-5.5 (xhigh)Step 5 PreviewLeader
Reasoning68.051.7GPT-5.5
Coding60.749.9GPT-5.5
Agents & tools61.849.7GPT-5.5
Maths69.560.1GPT-5.5
Knowledge63.553.7GPT-5.5
Instruction following74.0–not comparable
Human preference–63.1not comparable
Multimodal62.359.3GPT-5.5
Long context66.969.0Step 5 Preview
Composite–38.3not comparable

On one chart

Each domain on the index's own scale, where 50 is an average model. Click a domain to see the benchmarks behind it. Pick up to 5 models from the list.

2550 avg75ReasoningCodingAgents & toolsMathsKnowledgeLong contextMultimodalGPT-5.5, Reasoning: 68.0GPT-5.5, Coding: 60.7GPT-5.5, Agents & tools: 61.8GPT-5.5, Maths: 69.5GPT-5.5, Knowledge: 63.5GPT-5.5, Long context: 66.9GPT-5.5, Multimodal: 62.3Step 5 Preview, Reasoning: 51.7Step 5 Preview, Coding: 49.9Step 5 Preview, Agents & tools: 49.7Step 5 Preview, Maths: 60.1Step 5 Preview, Knowledge: 53.7Step 5 Preview, Long context: 69.0Step 5 Preview, Multimodal: 59.3

Not drawn, measured for fewer than two of these models: Instruction following, Human preference.

Model, click to add or removeIndex

Where sources disagree

Across the 26 benchmarks both have, GPT-5.5 leads 13, Step 5 Preview leads 12 and 1 is a tie. Every overall index that rates both puts GPT-5.5 ahead.

Overall indexGPT-5.5 (xhigh)Step 5 PreviewLeader
BenchLeader Index64.154.3GPT-5.5
Arena Text1481†1449GPT-5.5

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. Cost, tokens and time per benchmark task are measured: Artificial Analysis’ averages over its whole Intelligence Index run.

MeasureGPT-5.5 (xhigh)Step 5 Preview
Blended price per 1M tokens$11.25$1.43
Input / output per 1M$5.00 / $30.00$1.00 / $2.70
Cached input per 1M$0.500$0.105
Price per task: chat reply$0.011$0.0012
Price per task: summarize a 30-page report$0.078$0.014
Price per task: code edit$0.075$0.010
Price per task: agentic coding session$0.420$0.071
Price per task: structured extraction$0.016$0.0025
Agentic coding session, input mostly cached$0.217$0.030
Cost per benchmark task (AA Index)–$2.35
Output tokens per task (AA Index)–113k
Of which reasoning–80k
Time per task (AA Index)–14 min
Output speed70 tok/s135 tok/s
Time to first answer37.1 s22.8 s
Time to a complete answer104.3 s54.4 s

Each model is compared at its best-ranked reasoning-effort setting. GPT-5.5 (xhigh) scores 64.1 and takes 37 s to its first answer token; GPT-5.5 (high) scores 63.5 in 21 s, GPT-5.5 scores 61.2 in 3 s. Step 5 Preview scores 54.3 and takes 23 s to its first answer token. 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

166 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-5.5 (xhigh)Step 5 Preview
BenchLeader IndexBenchLeader64.154.3
Agents & tools scoreBenchLeader61.849.7
Coding scoreBenchLeader60.749.9
Instruction following scoreBenchLeader74.0–
Knowledge scoreBenchLeader63.553.7
Long context scoreBenchLeader66.969.0
Maths scoreBenchLeader69.560.1
Multimodal scoreBenchLeader62.359.3
Reasoning scoreBenchLeader68.051.7
Composite scoreBenchLeader–38.3
Human preference scoreBenchLeader–63.1
Blended price $/MBenchLeader$11.25$1.43
Output speedBenchLeader70 tok/s135 tok/s
Time to first answerBenchLeader37.1 s22.8 s
Context windowBenchLeader1,050,000 tokens1,000,000 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub90.7%†–
SimpleBenchSimpleBench69.0%†–
Arena Hard PromptsArena (LMArena)1499†1477
LiveBench 2.0 ReasoningLiveBench–83.8%
LiveBench 1.0 ReasoningLiveBench89.7%–
GPQA Diamond (AA)Artificial Analysis93.5%–
Humanity's Last Exam (AA)Artificial Analysis45.8%46.5%
HLE-Diamond (AA)Artificial Analysis–24.3%
GPQA Diamond (Vals)Vals AI93.2%–
Kagi LLM BenchmarkKagi LLM Benchmark88.8%†–
ARC-AGI-1ARC Prize95.0%–
ARC-AGI-2ARC Prize85.0%–
ARC-AGI-3ARC Prize0.4%†–
CritPtArtificial Analysis27.1%20.9%
CritPt v2 hard subset (AA)Artificial Analysis–32.5%
MysteryMechanismVals AI–18.5%
Chess PuzzlesEpoch AI Benchmarking Hub63.0%–
Mystery Game PuzzlesEpoch AI Benchmarking Hub56.0%–
CL-bench LifeEpoch AI Benchmarking Hub22.2%†–
LMCAEpoch AI Benchmarking Hub54.3%–
DTBenchEpoch AI Benchmarking Hub96.0%–
ForecastBenchForecastBench64.2%†–
BTF-3Epoch AI Benchmarking Hub14.3%†–
Coding
SciCodeSciCode55.8%58.9%
WeirdMLWeirdML84.9%–
Show all 166 benchmarks
MetricPublisherGPT-5.5 (xhigh)Step 5 Preview
Coding
FrontierCodeCognition43.0%†–
GSO-BenchGSO-Bench40.2%–
Arena CodingArena (LMArena)1510†1505
Arena WebDevArena (LMArena)15121573†
LiveBench 2.0 CodingLiveBench–67.6%
LiveBench 1.0 CodingLiveBench82.2%–
LiveCodeBenchVals AI85.3%–
IOIVals AI–38.1%
SWE-bench (Vals)Vals AI82.6%–
Code MigrationVals AI45.2%39.0%
Code Migration v1.1Vals AI–47.0%
ProgramBenchVals AI0.5%–
SWE-bench MultimodalVals AI–40.8%
Vibe Code Bench v1.1Vals AI69.8%70.4%
SWE Atlas: Codebase QnAScale AI SEAL45.4%–
SWE Atlas: RefactoringScale AI SEAL44.8%–
SWE Atlas: Test WritingScale AI SEAL42.6%–
MirrorCodeEpoch AI Benchmarking Hub23.3%–
Surface Evolver BenchEpoch AI Benchmarking Hub88.1%†–
DeepSWE v1.1Epoch AI Benchmarking Hub67.0%–
ALE-BenchEpoch AI Benchmarking Hub1943.0–
Terminal-Bench 4.0 (AA)Artificial Analysis14.7%33.3%
Terminal-Bench 2.1 (AA)Artificial Analysis84.3%–
GameBench 2 OverallDuelLab GameBench 248.8†–
GameBench 2 by reasoning settingDuelLab GameBench 259.7–
Design Arena WebsiteDesign Arena1248†–
FrontierCode 1.1 (AA)Artificial Analysis–38.4%
FrontierCode 2.0 (AA)Artificial Analysis–12.0%
Agents & tools
Terminal-BenchTerminal-Bench84.7%†–
OSWorld-Verified 2.0OSWorld13.0%–
Remote Labor IndexScale AI / CAIS6.3%†–
APEX-AgentsMercor55.1%†–
Arena AgentArena (LMArena)–-3.7
LiveBench Long AgenticLiveBench–19.4%
LiveBench BrowserLiveBench–24.8%
LiveBench Agentic CodingLiveBench54.0%–
Terminal-Bench HardArtificial Analysis60.6%–
τ²-Bench Telecom (AA)Artificial Analysis93.9%–
Terminal-Bench 2.1 (Vals)Vals AI76.4%†–
MCP AtlasScale AI SEAL75.3%–
HiL-BenchScale AI SEAL39.7%†–
τ³-bench Bankingτ²-bench44.6%–
GDPval-AA v2.1, normalised scoreArtificial Analysis–54.3%
GDPval-AA v2.1Artificial Analysis–1592
τ³-Banking (AA)Artificial Analysis39.0%–
ITBench SRE (AA)Artificial Analysis45.8%55.6%
Analyst Agent (AA)Artificial Analysis50.0%35.0%
APEX-Agents (AA)Artificial Analysis37.7%38.0%
Finance Agent v2Vals AI51.8%50.7%
Finance Agent v2.1Vals AI–58.9%
Harvey's Legal Agent Benchmark v1.1Vals AI–12.9%
Harvey's Legal Agent Benchmark v1Vals AI3.8%9.2%
Legal Research BenchVals AI40.4%40.4%
SkillsBenchVals AI62.2%–
SREBenchVals AI3.8%0.4%
Tax Agent BenchVals AI21.8%27.3%
Terminal-Bench 2.0 (Vals)Vals AI73.2%†–
Terminal-Bench 4.0 (Vals)Vals AI–31.8%
Terminal-Bench ScienceVals AI–2.9%
Time Horizon Index: KSPVals AI8.3%–
Arena SearchArena (LMArena)1226†–
DeepResearch BenchDeepResearch Bench54.0%†–
PostTrainBenchEpoch AI Benchmarking Hub23.9%–
ExploitBenchEpoch AI Benchmarking Hub47.4%†–
GBAEvalEpoch AI Benchmarking Hub53.2%†–
Vending-Bench 2Andon Labs7523.8†–
AutomationBenchArtificial Analysis47.3%51.0%
GDP.pdf (AA)Artificial Analysis21.2%14.8%
EnterpriseOps-GymArtificial Analysis46.6%47.2%
AA-Briefcase v1.1Artificial Analysis11351423
Design Arena AgenticDesign Arena1105†–
RoboDojo (LLM as robot policy)RoboDojo1.1†–
Terminal-Bench-Science 0.1 (AA)Artificial Analysis–2.4%
CWE-Bench (AA)Artificial Analysis–52.5%
DeepSec-Bench (AA)Artificial Analysis–15.8%
CyberGym end-to-end (AA)Artificial Analysis–74.8%
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub85.3%–
FrontierMath Tier 4Epoch AI Benchmarking Hub72.5%–
OTIS Mock AIMEEpoch AI Benchmarking Hub84.4%†–
ProofBenchVals AI50.0%42.0%
LiveBench MathematicsLiveBench95.9%–
AIME 2026MathArena100.0%–
HMMT February 2026MathArena98.5%–
USAMO 2026MathArena98.2%–
MathArena ApexMathArena80.2%–
Arena MathsArena (LMArena)1500†1470
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub63.0%–
LiveBench 2.0 Data AnalysisLiveBench–63.5%
LiveBench ResearchLiveBench–75.5%
LiveBench 1.0 Data AnalysisLiveBench81.6%–
AA-Omniscience v1.1Artificial Analysis–16.4
MMLU-ProVals AI88.1%–
LegalBenchVals AI86.5%–
CorpFinVals AI68.4%–
TaxEvalVals AI75.0%–
BioMysteryBenchVals AI–67.4%
CaseLaw v2Vals AI66.2%–
Excel Modeling BenchmarkVals AI64.5%57.1%
Excel Modeling Benchmark v1.1Vals AI–69.5%
MedCodeVals AI49.1%–
MedScribeVals AI86.9%–
Public Benefits Bench v1.1Vals AI60.9%58.1%
DrugDiscoveryBenchScale AI SEAL51.6%–
EBR-benchEpoch AI Benchmarking Hub34.3%–
GDP.pdfEpoch AI Benchmarking Hub26.0%–
AA-Omniscience v1.1: accuracyArtificial Analysis–36.4%
AA-Omniscience v1.1: non-hallucinationArtificial Analysis–68.7%
Instruction following
LiveBench LanguageLiveBench87.4%–
LiveBench Instruction FollowingLiveBench70.7%–
IFBenchArtificial Analysis75.8%–
Arena Instruction FollowingArena (LMArena)1475†1450
Human preference
Arena TextArena (LMArena)1476†1449
EQ-Bench 4EQ-Bench1295†–
Arena Creative WritingArena (LMArena)1448†1413
Arena Multi-turnArena (LMArena)1484†1445
Arena Longer QueriesArena (LMArena)1486†1461
Multimodal
Arena VisionArena (LMArena)1296†1263
LiveBench DesignLiveBench–70.8%
MMMU-ProArtificial Analysis79.9%76.4%
MMMU-Pro (Vals)Vals AI88.3%–
MortgageTaxVals AI68.8%–
Blueprint-Bench 2Epoch AI Benchmarking Hub36.2%†–
Code2Video-AAArtificial Analysis1000821
AA-3DArtificial Analysis–859
Long context
AA-LCR v1.1Artificial Analysis84.3%88.3%
Arena DocumentArena (LMArena)1479†–
MLCRArtificial Analysis28.9%18.3%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub160.1†–
LiveBench 2.0LiveBench–54.9%
LiveBench 1.0LiveBench80.2%–
AA Intelligence Index v5.0Artificial Analysis–28.5
AA Intelligence Index v4.3.2Artificial Analysis38.443.7
AA Progress Index v1Artificial Analysis320318.2
Vals IndexVals AI–54.8
Vals Finance IndexVals AI–55.4%
Vals RSI IndexVals AI16.5%–
Vals Science IndexVals AI–29.6%
Vals Multimodal IndexVals AI68.1%–
AA Cyber IndexArtificial Analysis–47.7
Safety & honesty
FORTRESSScale AI SEAL16.3%–
Metadata
AA Openness IndexArtificial Analysis–33.3

Data as of 2026-11-13. Best configuration of each model; every score links to its source on the model pages.

DuelLab GameBench 2, release gb2-20261110-2acac640a228 (https://benchmarks.duellab.org/releases/gb2-20261110-2acac640a228/), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Scores mapped to BenchLeader model names; not endorsed by DuelLab.

What changed

  • GPT-5.5 (xhigh): BenchLeader Index 64.6 → 64.1.
  • GPT-5.5 (xhigh): 1 score revision.
  • Step 5 Preview: 1 score revision.
  • GPT-5.5 (xhigh): 1 new result (MirrorCode).
  • Step 5 Preview: 7 score revisions.
  • GPT-5.5 (xhigh): 1 score revision.
  • Step 5 Preview: 2 new results (Vals Index, Harvey's Legal Agent Benchmark v1.1).
  • Step 5 Preview: 1 score revision.
  • Step 5 Preview: BenchLeader Index 58.0 → 54.7.
  • GPT-5.5 (xhigh): 1 new result (AA Progress Index v1).

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

GPT-5.5 vs Step 5 Preview: questions

Is GPT-5.5 better than Step 5 Preview?
GPT-5.5 (xhigh) leads on quality: 64.1 vs 54.3. The BenchLeader Index combines every independent quality benchmark; GPT-5.5 (xhigh) is ahead overall as of 13 Nov 2026, but check the category scores for your use.
GPT-5.5 vs Step 5 Preview: which is cheaper, and will that change?
Step 5 Preview is cheaper today: $1.43 against $11.25 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is GPT-5.5 or Step 5 Preview better for coding?
GPT-5.5 scores higher in coding (61 vs 50 on the category index, where 50 is average). On SciCode, the top shared coding benchmark, it is 55.8% for GPT-5.5 against 58.9% for Step 5 Preview.
Which is faster, GPT-5.5 or Step 5 Preview?
Step 5 Preview streams ~1.5× faster (135 vs 70 output tokens per second, Artificial Analysis 7-day median).
Is GPT-5.5 or Step 5 Preview better for agents and tool use?
GPT-5.5 scores higher in agentic tasks (62 vs 50 on the category index, where 50 is average).
More questions (4)
Which is better for long documents?
Step 5 Preview scores higher on long-context benchmarks (69 vs 67). Both take about 1.1M tokens: GPT-5.5 1,050,000, Step 5 Preview 1,000,000.
Which has lower latency?
Step 5 Preview answers first: 22.8 s against 37.1 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 GPT-5.5 vs Step 5 Preview?
Across the 26 benchmarks both have, GPT-5.5 leads 13, Step 5 Preview leads 12 and 1 is a tie. Every overall index that rates both puts GPT-5.5 ahead.
When was Step 5 Preview released?
Step 5 Preview was released on 18 Sep 2026.