Model comparison
Claude Fable 5.1 vs Muse Spark 1.3
ClaudeCompare published specifications, vendor API list prices and measured Borg performance. Both models are included in Borg.
Claude Fable 5.1
Muse Spark 1.3
Included in Borg
At a glance
| Specification | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| Provider | Anthropic | Meta |
| Release | — | 2026-09-02 Vendor source |
| Context | 1,000,000 tokens Vendor source | 1,048,576 tokens Vendor source |
| Modalities | Input: text, image; output: text | Input: text, image, video, audio, PDF; output: text |
| Reasoning / thinking modes | Yes / Not published | Yes / Not published |
| Open weights | No | No |
| Vendor API list price / 1M tokens | $10 input / $50 output | $1.25 input / $4.25 output |
| Borg | Included in Borg subscription | Included in Borg subscription |
Anthropic
MetaNot published by the vendor: release.
Measured on Borg
Metrics are not directly comparable to vendor benchmark claims. Models served different requests; this is observed gateway traffic, not a controlled head-to-head test.
Time to first token (gateway proxy)
Output tokens per second (whole turn)
| Metric | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| Time to first token (gateway proxy) p50 | 6015 ms (2192 samples) | 5938 ms (1912 samples) |
| Tokens per second (end to end) p50 | 55.9 output tokens per second (7156 samples) | 26.2 output tokens per second (1928 samples) |
| Request success rate | 99.9% (6283 samples) | Not published |
| Coding bench pass rate | Not published | Not published |
Measurement window, samples and methodology
The fleet reference is the median of published model medians, not a request-weighted result. Prompt lengths, reasoning settings and traffic differ between models.
Claude Fable 5.1: Measured on Borg: SearchAtlas AI Gateway production request logs. 30-day window ending 2026-10-08; 7924 requests. Minimum 100 samples per published request metric.
Muse Spark 1.3: Measured on Borg: SearchAtlas AI Gateway production request logs. 30-day window ending 2026-10-08; 2340 requests. Minimum 100 samples per published request metric.
Completion speed covers the whole turn including queueing and reasoning time; it is not a streaming tokens-per-second figure.
- Time to first token (gateway proxy): time until the first streamed response event reaches the gateway; our closest available measure of time to first token
- Tokens per second (end to end): tokens per second, end to end: provider-reported output tokens divided by the whole turn's elapsed time, including queueing and reasoning; not a streaming per-token rate
How to choose
Claude Fable 5.1 is listed for long-horizon coding agents tackling difficult repositories, whereas Muse Spark 1.3 is listed for long-horizon coding with changing requirements. Choosing between Claude Fable 5.1 and Muse Spark 1.3 requires checking published specifications against observed Borg traffic for your workflow.
Key differences
| Spec | Claude Fable 5.1 | Muse Spark 1.3 |
|---|---|---|
| Context window | 1,000,000 tokens Vendor source | 1,048,576 tokens Vendor source Larger context |
| Reasoning modes | Yes / Not published | Yes / Not published |
| Release date | Not published | 2026-09-02 Vendor source |
| API price input / 1M | 10 | 1.25 Lower listed rate |
| API price output / 1M | 50 | 4.25 Lower listed rate |
| Time to first token (gateway proxy) | 6015 ms (2192 samples) | 5938 ms (1912 samples) Lower median |
| Output tokens per second (whole turn) | 55.9 output tokens/s (whole turn) (7156 samples) Higher measured rate | 26.2 output tokens/s (whole turn) (1928 samples) |
| Request success | 99.9% (6283 samples) | Not published |
| Coding bench | Not published | Not published |
FAQ
How do Claude Fable 5.1 and Muse Spark 1.3 compare for coding?
Claude Fable 5.1 has a Borg coding benchmark of not published; Muse Spark 1.3 has not published. The Claude Fable 5.1–Muse Spark 1.3 coding comparison cannot establish an overall winner from this small test alone.
How quickly do Claude Fable 5.1 and Muse Spark 1.3 start responding on Borg?
Borg median first response for Claude Fable 5.1 is 6,015 ms; for Muse Spark 1.3 it is 5,938 ms. The Claude Fable 5.1–Muse Spark 1.3 gateway medians are observations, not guaranteed latency for individual requests.
What are the API prices for Claude Fable 5.1 and Muse Spark 1.3?
The listed API rate for Claude Fable 5.1 is $10 input / $50 output per 1M tokens; for Muse Spark 1.3 it is $1.25 input / $4.25 output per 1M tokens. Neither Claude Fable 5.1 nor Muse Spark 1.3 has its Borg subscription charge represented by those provider API rates. Claude Fable 5.1 vendor source · Muse Spark 1.3 vendor source
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