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Claude Fable 5 vs GPT-5.5 Pro

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

Claude Fable 5 is the cheaper of the two; neither can be ranked on quality here.

GPT-5.5 Pro does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

anthropic

Claude Fable 5

Blended / 1M
$20.00
Context
1M
Released
Jun 9, 2026
Overall score
83.0
reasoningtool callingimage inputfile inputprompt caching

openai

GPT-5.5 Pro

Blended / 1M
$67.50
Context
1.1M
Released
Apr 24, 2026
Overall score
Not evaluated
reasoningtool callingfile inputimage input

Specs and pricing

MetricClaude Fable 5GPT-5.5 Pro
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

83.0
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.7925
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$20.00win$67.50
Input price / 1M$10.00win$30.00
Output price / 1M$50.00win$180.00
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$1.00
Context window1M1.1M
Max output tokens128K128K

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Claude Fable 5 on top, GPT-5.5 Pro below, both out of 100.

Agentic coding
62.2
Coding
86.0
Reasoning
89.7
Mathematics
96.0
Data analysis
80.5
Language
90.7
Instruction following
75.8

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadClaude Fable 5GPT-5.5 Pro
Support chatbot

1.2K in / 400 out × 200K requests

$5,752/mo$21,600/mo
RAG assistant

8K in / 600 out × 100K requests

$7,400/mo$34,800/mo
Coding agent

40K in / 4K out × 20K requests

$6,960/mo$38,400/mo
Document extraction

20K in / 1.5K out × 50K requests

$13,300/mo$43,500/mo
Bulk classification

500 in / 20 out × 5M requests

$25,500/mo$93,000/mo
Run these two through the cost calculator

Which should you pick?

You are cost-constrained

Claude Fable 5

Cheaper on blended list price at $20.00 per million tokens.

Claude Fable 5 vs GPT-5.5 Pro FAQ

Which is better, Claude Fable 5 or GPT-5.5 Pro?

Claude Fable 5 is the cheaper of the two; neither can be ranked on quality here. GPT-5.5 Pro does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

Is Claude Fable 5 cheaper than GPT-5.5 Pro?

Claude Fable 5 is cheaper. On a 3:1 input:output blend, Claude Fable 5 lists at $20.00 per million tokens and GPT-5.5 Pro at $67.50 — Claude Fable 5 is 3.4× cheaper. Input and output are priced separately — Claude Fable 5 charges $10.00 in and $50.00 out, GPT-5.5 Pro charges $30.00 and $180.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Does Claude Fable 5 or GPT-5.5 Pro have a bigger context window?

They are effectively the same — 1M for Claude Fable 5 and 1.1M for GPT-5.5 Pro.

Do Claude Fable 5 and GPT-5.5 Pro support prompt caching?

Claude Fable 5 publishes a cached-input rate of $1.00 per million tokens against a full input rate of $10.00. The catalogue lists no separate cached rate for GPT-5.5 Pro, which means the provider does not price it separately here — not that caching is unavailable.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.