// head_to_head
Claude Fable 5 vs Sonar Reasoning 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.
Sonar Reasoning Pro is the cheaper of the two; neither can be ranked on quality here.
Sonar Reasoning 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
perplexity
Sonar Reasoning Pro
- Blended / 1M
- $3.50
- Context
- 128K
- Released
- Mar 7, 2025
- Overall score
- Not evaluated
Specs and pricing
| Metric | Claude Fable 5 | Sonar Reasoning 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. | $20.00 | $3.50win |
| Input price / 1M | $10.00 | $2.00win |
| Output price / 1M | $50.00 | $8.00win |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $1.00 | — |
| Context window | 1Mwin | 128K |
| Max output tokens | 128K | 115K |
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, Sonar Reasoning Pro 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 | Sonar Reasoning Pro |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $5,752/mo | $1,120/mo |
| RAG assistant 8K in / 600 out × 100K requests | $7,400/mo | $2,080/mo |
| Coding agent 40K in / 4K out × 20K requests | $6,960/mo | $2,240/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $13,300/mo | $2,600/mo |
| Bulk classification 500 in / 20 out × 5M requests | $25,500/mo | $5,800/mo |
Which should you pick?
You need to fit large documents in one call
Claude Fable 5
Wider context window — 1M against 128K.
You are cost-constrained
Sonar Reasoning Pro
Cheaper on blended list price at $3.50 per million tokens.
Claude Fable 5 vs Sonar Reasoning Pro FAQ
Which is better, Claude Fable 5 or Sonar Reasoning Pro?
Sonar Reasoning Pro is the cheaper of the two; neither can be ranked on quality here. Sonar Reasoning 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 Sonar Reasoning Pro?
Sonar Reasoning Pro is cheaper. On a 3:1 input:output blend, Claude Fable 5 lists at $20.00 per million tokens and Sonar Reasoning Pro at $3.50 — Sonar Reasoning Pro is 5.7× cheaper. Input and output are priced separately — Claude Fable 5 charges $10.00 in and $50.00 out, Sonar Reasoning Pro charges $2.00 and $8.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Does Claude Fable 5 or Sonar Reasoning Pro have a bigger context window?
Claude Fable 5 has the larger context window: 1M for Claude Fable 5 against 128K for Sonar Reasoning Pro. 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 and Sonar Reasoning 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 Sonar Reasoning 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.
- 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.