Skip to content
Leaderboard / OpenAI

GPT-5.5

OpenAI High CLOSED Proprietary
Other settings:Default · 77xHigh, Codex HarnessHigh, Codex HarnessCodex Harness
Verdict

GPT-5.5 is a top-tier model: #10 of 406 by SIscope score. Strong at everything it's been tested on, especially following instructions. On the pricey side: costs more than 97% of priced models.

SIscope score
92
#10 of 406
Human-vote rank
#31
of 419 · score 1472
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.

Coding92
Agents & toolsNo data yet–
Reasoning & knowledge95
Math91
Chat quality93
Following instructions95

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

Human-vote score over time

Text arena, recent updates.

146514731480Oct 20: 1471.4 (rank #30)Oct 22: 1471.5 (rank #30)Oct 28: 1471.6 (rank #31)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.

No Epoch AI runs for this model yet.

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
#31 of 41914721468–147569,377Oct 28, 2026
WebDev arena
Building web apps, blind human votes
Not on this board yet
Vision arena
Questions about images, blind human votes
#25 of 16712931287–129927,067Oct 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.