GPT-5.5

openai/gpt-5.5-20260423

OpenAI: GPT-5.5 accepts file, image, and text inputs and provides text outputs. It has a context length of 1,050,000 tokens and supports tools and reasoning. Pricing is $5 per million input tokens and $30 per million output tokens.

  • tool use
  • structured outputs
  • reasoning

At a glance

provideropenai
releasedMar 5, 2026
context1.1M
input / M$5

Specifications

What the API gives you

Context window
1.1M tokens
Max output
128K tokens
Input price
$5 / 1M tokens
Output price
$30 / 1M tokens
Cache read
$0.50 / 1M tokens
Modalities
file, image, text → text
Knowledge cutoff
Dec 1, 2025
Released
Mar 5, 2026

Measured evidence

Public benchmark record

Design Arena Coding
1260 Elo2026-10-21
Design Arena Full-stack Agent
1089 Elo2026-10-14
Design Arena UI
1260 Elo2026-10-21
Design Arena Web-app Agent
1116 Elo2026-10-21
Design Arena Website
1257 Elo2026-10-21
FACTS Grounding
76.2%2026-10-21
FrontierMath Tiers 1-3 (Epoch AI)‡
85.3% ± 2.12026-06-11xhigh effort, evaluated 2026-06-11
GPQA Diamond (Epoch AI)‡
77.3% ± 32026-08-07none effort, evaluated 2026-08-07
GPQA Diamond (Epoch AI)‡
90.7% ± 1.82026-05-05low effort, evaluated 2026-05-05
LiveBench Agentic Coding
54.0%2026-10-18
LiveBench Coding
82.2%2026-10-18
LiveBench Data Analysis
81.6%2026-10-18
LiveBench Instruction Following
70.7%2026-10-18
LiveBench Language
87.4%2026-10-18
LiveBench Math
95.9%2026-10-18
LiveBench Reasoning
89.7%2026-10-18
LMArena Agent‡
3.12026-10-20xhigh effort
LMArena Agent Bash Recovery‡
9.52026-10-08xhigh effort
LMArena Agent Steerability‡
32026-10-20xhigh effort
LMArena Agent Task Outcome‡
-2.42026-10-20xhigh effort
LMArena Agent Tool Hallucination‡
0.62026-10-20xhigh effort
LMArena Creative Writing‡
1455 Elo2026-10-20high effort
LMArena Instruction Following‡
1478 Elo2026-10-20high effort
LMArena Long Query‡
1484 Elo2026-10-20high effort
LMArena Math‡
1479 Elo2026-10-20high effort
LMArena Text‡
1481 Elo2026-10-20high effort
LMArena Text Factuality‡
1486 Elo2026-10-20high effort
LMArena Vision‡
1282 Elo2026-10-19high effort
LMArena Vision Diagrams‡
1315 Elo2026-10-19high effort
LMArena Vision OCR‡
1297 Elo2026-10-19high effort
LMArena WebDev
1456 Elo2026-10-19
LMArena WebDev Image-to-Web
1503 Elo2026-10-19
OTIS Mock AIME (Epoch AI)‡
84.4% ± 5.52026-08-07low effort, evaluated 2026-08-07
SimpleQA Verified (Epoch AI)‡
63% ± 1.52026-08-27xhigh effort, evaluated 2026-08-27
tau2-bench (1.0.1)‡
44.6%2026-07-22xhigh effort, evaluated 2026-07-22

LMArena data licensed CC-BY-4.0. Aider (Apache-2.0) and SWE-bench (MIT) are open. Design Arena uses blind human preference. ‡ Submitted scaffold plus model result. Compare the harness and effort settings, not only the model name.

Task evidence

How broad is the support?

Each status is exact to this model version and the selected task. Official release claims remain provisional.

  • Best LLM for Competition MathEstablished evidence

    100% of intended weighted task evidence across 4 independent sources. 6 of 6 configured evaluation feeds currently have results.

  • Best LLM for Business WritingEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for Logic & Problem SolvingEstablished evidence

    100% of intended weighted task evidence across 3 independent sources. 5 of 5 configured evaluation feeds currently have results.

  • Best LLM for Marketing CopyEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for Chat & RoleplayEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for Creative WritingEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

Show all 45 tasks
  • Best LLM for Frontend & UIEstablished evidence

    100% of intended weighted task evidence across 3 independent sources. 6 of 6 configured evaluation feeds currently have results.

  • Best LLM for WritingEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for Roleplay & CharacterEstablished evidence

    100% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for Math & ReasoningEstablished evidence

    100% of intended weighted task evidence across 5 independent sources. 7 of 7 configured evaluation feeds currently have results.

  • Best LLM for a General AssistantEstablished evidence

    100% of intended weighted task evidence across 3 independent sources. 6 of 6 configured evaluation feeds currently have results.

  • Best LLM for Document SummarizationEstablished evidence

    85% of intended weighted task evidence across 3 independent sources. 5 of 6 configured evaluation feeds currently have results.

  • Best LLM for SummarizationEstablished evidence

    85% of intended weighted task evidence across 3 independent sources. 5 of 6 configured evaluation feeds currently have results.

  • Best LLM for Code CompletionEstablished evidence

    79% of intended weighted task evidence across 2 independent sources. 3 of 3 configured evaluation feeds currently have results.

  • Best Open-Weight LLM for Self-HostingEstablished evidence

    64% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Best LLM for Grounded RAGEstablished evidence

    62% of intended weighted task evidence across 3 independent sources. 5 of 7 configured evaluation feeds currently have results.

  • Best LLM for Image UnderstandingEstablished evidence

    61% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Best LLM for RAG & Long ContextEstablished evidence

    61% of intended weighted task evidence across 2 independent sources. 5 of 6 configured evaluation feeds currently have results.

  • Best LLM for Tool & Function CallingEstablished evidence

    58% of intended weighted task evidence across 2 independent sources. 6 of 7 configured evaluation feeds currently have results.

  • Best LLM for Fast SummariesEstablished evidence

    58% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Best Value LLMEstablished evidence

    58% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Best LLM for Agentic CodingEstablished evidence

    55% of intended weighted task evidence across 3 independent sources. 7 of 7 configured evaluation feeds currently have results.

  • Best LLM for CodingEstablished evidence

    53% of intended weighted task evidence across 3 independent sources. 7 of 7 configured evaluation feeds currently have results.

  • Best LLM for Literary TranslationEstablished evidence

    50% of intended weighted task evidence across 2 independent sources. 3 of 4 configured evaluation feeds currently have results.

  • Best LLM for Everyday TranslationEstablished evidence

    50% of intended weighted task evidence across 2 independent sources. 3 of 4 configured evaluation feeds currently have results.

  • Best LLM for TranslationEstablished evidence

    50% of intended weighted task evidence across 2 independent sources. 3 of 4 configured evaluation feeds currently have results.

  • Best Local LLM for CodingEstablished evidence

    47% of intended weighted task evidence across 2 independent sources. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for AI AgentsEstablished evidence

    43% of intended weighted task evidence across 3 independent sources. 9 of 9 configured evaluation feeds currently have results.

  • Best Cheap LLM for High VolumeEstablished evidence

    40% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Cheapest Capable LLMEstablished evidence

    40% of intended weighted task evidence across 2 independent sources. 2 of 3 configured evaluation feeds currently have results.

  • Best LLM for Autonomous AgentsEstablished evidence

    36% of intended weighted task evidence across 2 independent sources. 6 of 6 configured evaluation feeds currently have results.

  • Best LLM for JSON & Schema OutputEstablished evidence

    35% of intended weighted task evidence across 2 independent sources. 3 of 4 configured evaluation feeds currently have results.

  • Best LLM for Structured Data ExtractionEstablished evidence

    35% of intended weighted task evidence across 2 independent sources. 3 of 4 configured evaluation feeds currently have results.

  • Best LLM for Debugging & Code ReviewEstablished evidence

    33% of intended weighted task evidence across 2 independent sources. 5 of 5 configured evaluation feeds currently have results.

  • Best LLM for OCR & DocumentsProvisional evidence

    65% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Structured-output eval or VLMEvalKit tasks. 3 of 5 configured evaluation feeds currently have results.

  • Best LLM for Charts & DiagramsProvisional evidence

    65% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Structured-output eval or VLMEvalKit tasks. 3 of 5 configured evaluation feeds currently have results.

  • Best LLM for Vision & DocumentsProvisional evidence

    60% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Structured-output eval or VLMEvalKit tasks. 4 of 6 configured evaluation feeds currently have results.

  • Best LLM for Document ParsingProvisional evidence

    58% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Structured-output eval or VLMEvalKit tasks. 3 of 5 configured evaluation feeds currently have results.

  • Best LLM for Massive ContextProvisional evidence

    47% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from LongBench v2. 2 of 3 configured evaluation feeds currently have results.

  • Best LLM for Hermes AgentProvisional evidence

    29% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Berkeley Function Calling or SWE-rebench. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for OpenHandsProvisional evidence

    29% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Berkeley Function Calling or SWE-rebench. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for GooseProvisional evidence

    29% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Berkeley Function Calling or SWE-rebench. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for OpenClawProvisional evidence

    29% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Berkeley Function Calling or SWE-rebench. 4 of 4 configured evaluation feeds currently have results.

  • Best LLM for High-Volume ExtractionProvisional evidence

    21% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Route reliability or Structured-output eval. 1 of 3 configured evaluation feeds currently have results.

  • Best LLM for Computer & Browser UseProvisional evidence

    17% of intended weighted task evidence across 1 independent source; broader independent confirmation is still missing from Berkeley Function Calling or OSWorld Verified. 3 of 3 configured evaluation feeds currently have results.

Recommendation coverage

Where this model appears

Not currently included in a published recommendation. The task evidence panel above says exactly what is confirmed and what is still missing.

Catalog data via OpenRouter and models.dev. Last checked within the past 6 hours.