Which is better, Claude Fable 5.1 or GPT-5.5 Pro?

Claude Fable 5.1 scores higher on 2 of 4 shared quality measures, GPT-5.5 Pro on 0. 2 measures are too close to call. Claude Fable 5.1 costs about 70% less than GPT-5.5 Pro on a blended price of $20.00 against $67.50 per million tokens. Which one is better for you depends on your task and budget, so test both on your own work.

Which is cheaper, Claude Fable 5.1 or GPT-5.5 Pro?

Claude Fable 5.1 is cheaper on blended price: $20.00 per million tokens for Claude Fable 5.1 against $67.50 for GPT-5.5 Pro. For 100 chats of about 1,000 tokens in and 500 tokens back, that is about $3.50 for Claude Fable 5.1 and $12 for GPT-5.5 Pro.

Which can read longer documents, Claude Fable 5.1 or GPT-5.5 Pro?

Claude Fable 5.1 has a context window of 1M tokens and GPT-5.5 Pro has 1.1M tokens.

AI Rankings

Claude Fable 5.1 vs GPT-5.5 Pro: Scores, Price and Which to Choose

Side by side on every measure both models share: overall score, human votes, tests, price and context window. Close results are called too close to call.

Data updated 26 Oct 2026

Read the model pages for the full picture: Claude Fable 5.1 and GPT-5.5 Pro.

Side by side

A check mark shows the better side on each measure. Scores that are too close to call have no winner.

Claude Fable 5.1 compared with GPT-5.5 ProClaude Fable 5.1 against GPT-5.5 Pro on 6 measures. Claude Fable 5.1 is better on 3, GPT-5.5 Pro on 0, 3 are too close to call, 0 have no data for one side.

Claude Fable 5.1
GPT-5.5 Pro

Epoch Capabilities IndexToo close to call
Combined score over many tests. Bar shows where it sits between the lowest and highest score we track.
Claude Fable 5.1:
166.5
GPT-5.5 Pro:
162.9
ARC-AGI-2Claude Fable 5.1 leads
Visual puzzles where the AI must work out a new rule from a few examples and apply it.
Claude Fable 5.1:
Better: 90.0%
GPT-5.5 Pro:
84.6%
FrontierMath (Tiers 1-3)Claude Fable 5.1 leads
Original, very hard maths problems written by mathematicians.
Claude Fable 5.1:
Better: 90.2%
GPT-5.5 Pro:
87.7%
OTIS Mock AIMEToo close to call
Maths competition problems in the style of the US AIME exam, from the 2024 and 2025 sets.
Claude Fable 5.1:
100.0%
GPT-5.5 Pro:
100.0%
Blended price per million tokensClaude Fable 5.1 costs less
Blended price: lower is better.
Claude Fable 5.1:
Better: $20.00
GPT-5.5 Pro:
$67.50
Context windowToo close to call
How much text it can read at once.
Claude Fable 5.1:
1M tokens
GPT-5.5 Pro:
1.1M tokens

Data updated 26 Oct 2026. Only measures that both models have are shown.

The numbers

Claude Fable 5.1 against GPT-5.5 Pro, measure by measure. A check mark shows the better side.
Measure	Claude Fable 5.1	GPT-5.5 Pro
Epoch Capabilities IndexToo close to call	166.5	162.9
ARC-AGI-2	90.0%	84.6%
FrontierMath (Tiers 1-3)	90.2%	87.7%
OTIS Mock AIMEToo close to call	100.0%	100.0%
Blended price per million tokens	$20.00	$67.50
Context windowToo close to call	1M tokens	1.1M tokens

What it costs in everyday terms

Estimate for 100 chats of about 1,000 tokens in and 500 tokens back, from list prices. Your bill depends on how you use it.

100 chats with Claude Fable 5.1: $3.50; Blended price $20.00 per million tokens.
100 chats with GPT-5.5 Pro: $12; Blended price $67.50 per million tokens.

Who should pick which

Pick Claude Fable 5.1 if these matter most

ARC-AGI-2: 90.0% against 84.6%
FrontierMath (Tiers 1-3): 90.2% against 87.7%
Blended price per million tokens: $20.00 against $67.50

Pick GPT-5.5 Pro if these matter most

It does not lead clearly on any measure we hold for both models.

Too close to call: Epoch Capabilities Index, OTIS Mock AIME, Context window.

Scores come from tests and votes, not from your own work. Try both on a task you care about before you commit.

Go deeper

Claude Fable 5.1: full page

GPT-5.5 Pro: full page

Questions about this comparison

Which is better, Claude Fable 5.1 or GPT-5.5 Pro?: Claude Fable 5.1 scores higher on 2 of 4 shared quality measures, GPT-5.5 Pro on 0. 2 measures are too close to call. Claude Fable 5.1 costs about 70% less than GPT-5.5 Pro on a blended price of $20.00 against $67.50 per million tokens. Which one is better for you depends on your task and budget, so test both on your own work.
Which is cheaper, Claude Fable 5.1 or GPT-5.5 Pro?: Claude Fable 5.1 is cheaper on blended price: $20.00 per million tokens for Claude Fable 5.1 against $67.50 for GPT-5.5 Pro. For 100 chats of about 1,000 tokens in and 500 tokens back, that is about $3.50 for Claude Fable 5.1 and $12 for GPT-5.5 Pro.
Which can read longer documents, Claude Fable 5.1 or GPT-5.5 Pro?: Claude Fable 5.1 has a context window of 1M tokens and GPT-5.5 Pro has 1.1M tokens.

Where this data comes from

Epoch AI: Benchmark data: Epoch AI, 'Capabilities & benchmarking', epoch.ai/benchmarks (CC BY 4.0). We match models across sources, rank them and show them in charts. Scores are not changed. Epoch AI does not endorse this site.
Arena (formerly LMArena): Human-preference ratings: Arena (arena.ai) leaderboard dataset, CC BY 4.0. We keep the latest published ratings, match them to models from other sources and rank them. Ratings are not changed. Arena does not endorse this site.
LiteLLM model price list: Prices and context windows: LiteLLM model price list (github.com/BerriAI/litellm, MIT licence). We use the model maker's own price entry when there is one. Prices change often, so always confirm on the maker's site before you buy.

Newest data on this page: 26 Oct 2026. Prices are list prices and change often, so confirm on the maker's site before you buy. Sponsors never change a score or an order. How we calculate this · Report a mistake