Claude Haiku 4.5 vs Muse Spark Open.
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 Haiku 4.5 | Muse Spark Open | Winner |
|---|---|---|---|
| League Score | 26.9 | 27.4 | Muse Spark Open |
| Coding (SWE-bench %) | 73.3 | — | — |
| Reasoning (GPQA %) | — | — | — |
| Context (tokens) | 200000 | 1048576 | Muse Spark Open |
| Speed (tok/s) | — | — | — |
Tale of the tape
| Spec | Claude Haiku 4.5 | Muse Spark Open |
|---|---|---|
| Maker | Anthropic | Meta |
| Released | Oct 15, 2025 | Oct 15, 2026 |
| League Score | 27 | 27 |
| Context | 200,000 tokens | 1,048,576 tokens |
| Max output | 64,000 | — |
| $/1M input | $1.00 | — |
| $/1M output | $5.00 | — |
| Weights | Closed | Open |
| Speed | — | — |
Head-to-head benchmarks (shared only)
| Benchmark | Claude Haiku 4.5 | Muse Spark Open |
|---|---|---|
| LiveBench overall | 46.0 | 51.6 |
Cost at three workloads
| Workload | Claude Haiku 4.5 | Muse Spark Open |
|---|---|---|
| Light — 1M in / 250K out | $2.25 | — |
| Standard — 10M in / 2.5M out | $22.50 | — |
| Long-context — 50M in / 5M out | $75.00 | — |
The pick
Pick Claude Haiku 4.5 if coding is the priority.
Pick Muse Spark Open if you want the higher overall League Score; you need the bigger context window; you want downloadable weights / self-hosting.
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 Haiku 4.5 or Muse Spark Open?
On overall League Score they are effectively tied — Claude Haiku 4.5 scores 27 and Muse Spark Open scores 27. The category verdicts on this page are where the real differences live.
Which is cheaper, Claude Haiku 4.5 or Muse Spark Open?
Only Claude Haiku 4.5 has published API pricing in our database ($2.00 blended per 1M tokens); Muse Spark Open has no tracked API price, so a like-for-like cost verdict is not possible.
Which has the bigger context window, Claude Haiku 4.5 or Muse Spark Open?
Muse Spark Open, with 1M of context against 200K for Claude Haiku 4.5.
Are Claude Haiku 4.5 and Muse Spark Open open source?
Claude Haiku 4.5 is closed weights — API access only; Muse Spark Open is open weights — it can be downloaded and self-hosted.