// head_to_head
Claude Fable 5.1 vs GPT-5.4 Nano
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.
Claude Fable 5.1 scores higher, GPT-5.4 Nano costs less — it depends on your workload.
Claude Fable 5.1 is ahead by 13.8 points overall, and GPT-5.4 Nano lists 43× cheaper per blended million tokens. Whether 13.8 points is worth that depends on how much a wrong answer costs you. GPT-5.4 Nano also leads on measured cost per point of capability, at $0.0500 per point.
anthropic
Claude Fable 5.1
- Blended / 1M
- $20.00
- Context
- 1M
- Released
- Sep 1, 2026
- Overall score
- 83.4
openai
GPT-5.4 Nano
- Blended / 1M
- $0.463
- Context
- 400K
- Released
- Mar 17, 2026
- Overall score
- 69.6
Specs and pricing
| Metric | Claude Fable 5.1 | GPT-5.4 Nano |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 83.4win | 69.6 |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | $0.6668 | $0.0500win |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $20.00 | $0.463win |
| Input price / 1M | $10.00 | $0.200win |
| Output price / 1M | $50.00 | $1.25win |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.250 | $0.020win |
| Context window | 1Mwin | 400K |
| Max output tokens | 128K | 128K |
Benchmarks by category
An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Claude Fable 5.1 on top, GPT-5.4 Nano below, both out of 100.
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.
| Workload | Claude Fable 5.1 | GPT-5.4 Nano |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $5698.00/mo | $135.04/mo |
| RAG assistant 8K in / 600 out × 100K requests | $7100.00/mo | $163.00/mo |
| Coding agent 40K in / 4K out × 20K requests | $6540.00/mo | $159.20/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $13,263/mo | $284.75/mo |
| Bulk classification 500 in / 20 out × 5M requests | $25,125/mo | $535.00/mo |
Which should you pick?
You are running this at volume
GPT-5.4 Nano
Lowest measured cost per point of capability at $0.0500 per point — the gap compounds with every request.
Quality matters more than the bill
Claude Fable 5.1
Highest overall LiveBench score of the two at 83.4.
The workload is coding or agentic work
Claude Fable 5.1
Leads on agentic coding — 66.1 against 46.8.
You need to fit large documents in one call
Claude Fable 5.1
Wider context window — 1M against 400K.
Claude Fable 5.1 vs GPT-5.4 Nano FAQ
Which is better, Claude Fable 5.1 or GPT-5.4 Nano?
Claude Fable 5.1 scores higher, GPT-5.4 Nano costs less — it depends on your workload. Claude Fable 5.1 is ahead by 13.8 points overall, and GPT-5.4 Nano lists 43× cheaper per blended million tokens. Whether 13.8 points is worth that depends on how much a wrong answer costs you. GPT-5.4 Nano also leads on measured cost per point of capability, at $0.0500 per point.
Is Claude Fable 5.1 cheaper than GPT-5.4 Nano?
GPT-5.4 Nano is cheaper. On a 3:1 input:output blend, Claude Fable 5.1 lists at $20.00 per million tokens and GPT-5.4 Nano at $0.463 — GPT-5.4 Nano is 43× cheaper. Input and output are priced separately — Claude Fable 5.1 charges $10.00 in and $50.00 out, GPT-5.4 Nano charges $0.200 and $1.25 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Claude Fable 5.1 vs GPT-5.4 Nano: which scores higher on benchmarks?
Claude Fable 5.1 scores 83.4 and GPT-5.4 Nano scores 69.6 overall on LiveBench, the mean of its seven categories. That is a 13.8-point lead for Claude Fable 5.1. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.
Which gives better value for money, Claude Fable 5.1 or GPT-5.4 Nano?
GPT-5.4 Nano. Cost per point divides the measured dollars LiveBench spent running the benchmark by the score it earned, so it captures something token pricing misses: a reasoning model can emit many times more tokens than its per-token rate suggests. Claude Fable 5.1 works out at $0.6668 per point and GPT-5.4 Nano at $0.0500.
Does Claude Fable 5.1 or GPT-5.4 Nano have a bigger context window?
Claude Fable 5.1 has the larger context window: 1M for Claude Fable 5.1 against 400K for GPT-5.4 Nano. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.
Do Claude Fable 5.1 and GPT-5.4 Nano support prompt caching?
Both publish a cached-input rate: $0.250 per million for Claude Fable 5.1 and $0.020 for GPT-5.4 Nano, against full input rates of $10.00 and $0.200. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.
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.
- Scores — LiveBench 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.