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Leaderboard / OpenAI

GPT-5.5

OpenAI CLOSED Proprietary
Other settings:High · 92xHigh, Codex HarnessHigh, Codex HarnessCodex Harness
Verdict

GPT-5.5 is a strong all-rounder: #56 of 406 by SIscope score. Strongest at following instructions, weaker at math. On the pricey side: costs more than 97% of priced models.

SIscope score
77
#56 of 406
Human-vote rank
#36
of 419 · score 1467
Price per 1M tokens, blended
$11
$5 in · $30 out
Context window
1.1M
1,050,000 tokens

Shape

Each spoke is a category, 0 at the centre, 100 at the edge.

CodingAgentsno data yetReasoningMathChatInstructions

Category scores

Percentiles: 90 means better than about 90% of tested models.

Coding87
Agents & toolsNo data yet–
Reasoning & knowledge73
Math67
Chat quality92
Following instructions94

What goes into each category · Compare with DeepSeek V4.1 Flash

Human-vote score over time

Text arena, recent updates.

146014681475Oct 20: 1466.7 (rank #35)Oct 22: 1466.8 (rank #35)Oct 28: 1466.8 (rank #36)Oct 20Oct 28

Independent test runs

Run by Epoch AI on the same harness for every model. Bars show the share of questions answered correctly.

GPQA Diamond77%
PhD-level science multiple choice questions
Better than 53% of 333 tested models. Run Aug 7, 2026.
OTIS Mock AIME 2024-2558%
Competition maths problems in the style of AIME
Better than 39% of 313 tested models. Run Aug 7, 2026.

Human-vote arenas

People compare two anonymous answers and pick the better one. Scores work like chess ratings.

ArenaRankScoreRange (95%)VotesUpdated
Text arena
Everyday chat, blind human votes
#36 of 41914671463–147070,949Oct 28, 2026
WebDev arena
Building web apps, blind human votes
Not on this board yet
Vision arena
Questions about images, blind human votes
#21 of 16712971291–130328,781Oct 19, 2026
Agent arena
Real multi-step agent sessions
Not on this board yet

Source: Arena (formerly LMArena) leaderboard dataset, CC BY 4.0. Fetched Nov 4, 2026.

Price

Input
$5
per 1M tokens
Output
$30
per 1M tokens
Blended
$11
3 in : 1 out, per 1M
Context window
1.1M
max tokens per request
Speed
Coming soon
our own tests

List price from the OpenRouter models API (openai/gpt-5.5), Nov 4, 2026. Providers can charge differently.