Claude Fable 5.1 vs Muse Spark 1.3.
Verdict by category, tale of the tape, shared benchmarks only, and cost at three workloads — all from the tracked data.
Verdict by category
| Category | Claude Fable 5.1 | Muse Spark 1.3 | Winner |
|---|---|---|---|
| League Score | 97.3 | 68.8 | Claude Fable 5.1 |
| Coding (SWE-bench %) | — | — | — |
| Reasoning (GPQA %) | 93.7 | — | — |
| Context (tokens) | 1000000 | 1048576 | Muse Spark 1.3 |
| Speed (tok/s) | — | — | — |
| Price (blended $/1M) | $20.00 | $2.00 | Muse Spark 1.3 (cheaper) |
Tale of the tape
| Spec | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| Maker | Anthropic | Meta |
| Released | Sep 1, 2026 | Sep 2, 2026 |
| League Score | 97 | 69 |
| Context | 1,000,000 tokens | 1,048,576 tokens |
| Max output | 128,000 | 943,718 |
| $/1M input | $10.00 | $1.25 |
| $/1M output | $50.00 | $4.25 |
| Weights | Closed | Closed |
| Speed | — | — |
Head-to-head benchmarks (shared only)
| Benchmark | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| LiveBench overall | 88.0 | 74.9 |
Cost at three workloads
| Workload | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| Light — 1M in / 250K out | $22.50 | $2.31 |
| Standard — 10M in / 2.5M out | $225.00 | $23.12 |
| Long-context — 50M in / 5M out | $750.00 | $83.75 |
The pick
Pick Claude Fable 5.1 if you want the higher overall League Score.
Pick Muse Spark 1.3 if you need the bigger context window; you want the lower running cost.
All figures from the model database — sources and dates on each model page. Cost your own workload or compare a different pair.
Frequently asked questions
Which is better overall, Claude Fable 5.1 or Muse Spark 1.3?
Claude Fable 5.1 leads on overall League Score, 97 to 69 — a gap of 28 points on a composite of sourced benchmarks. That is overall form, not every category: check the per-category verdicts before choosing.
Which is cheaper, Claude Fable 5.1 or Muse Spark 1.3?
Muse Spark 1.3 is cheaper: $2.00 vs $20.00 blended per 1M tokens (3:1 input/output mix) — about 10.0x less per token.
Which has the bigger context window, Claude Fable 5.1 or Muse Spark 1.3?
Muse Spark 1.3, with 1M of context against 1M for Claude Fable 5.1.
Are Claude Fable 5.1 and Muse Spark 1.3 open source?
Claude Fable 5.1 is closed weights — API access only; Muse Spark 1.3 is closed weights — API access only.