Choose Anthropic: Claude Sonnet 4.5 if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
Anthropic: Claude Sonnet 4.5 vs Meta: Muse Spark 1.3
Meta: Muse Spark 1.3 comes out ahead on the data we track: 3 advantages and none for Anthropic: Claude Sonnet 4.5.
Key numbers
| Spec | Anthropic: Claude Sonnet 4.5 | Meta: Muse Spark 1.3 |
|---|---|---|
| Provider | Anthropic | Meta |
| Input price (per 1M tokens) | $3.00 | $1.25 |
| Output price (per 1M tokens) | $15.00 | $4.25 |
| Blended price (3:1 input/output) | $6.00 | $2.00 |
| Cheaper than … of all models we track | 8% | 25% |
| Context window | 1M tokens (~1,500 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 69% | 80% |
| Max output per response | 64K tokens (~48,000 words) | 944K tokens (~707,800 words) |
| Input types | text, image, file | text, image, video, file |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-09-29 | 2026-09-02 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | Anthropic: Claude Sonnet 4.5 | Meta: Muse Spark 1.3 | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $525 | $179 | Meta: Muse Spark 1.3 saves $346 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $510 | $193 | Meta: Muse Spark 1.3 saves $317 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $540 | $201 | Meta: Muse Spark 1.3 saves $339 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $330 | $126 | Meta: Muse Spark 1.3 saves $205 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $165 | $66.75 | Meta: Muse Spark 1.3 saves $98.25 |
Capabilities side by side
| Capability | Anthropic: Claude Sonnet 4.5 | Meta: Muse Spark 1.3 | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | ✓ Yes | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | ✓ Yes | ✓ Yes | answer from live web results |
| Seed (reproducible sampling) | — | — | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- Anthropic: Claude Sonnet 4.5: price unchanged since we started tracking it on 2026-03-10.
- Meta: Muse Spark 1.3: price unchanged since we started tracking it on 2026-09-03.
Which should you choose?
Choose Meta: Muse Spark 1.3 if…
- cost matters at scale — it is 67% cheaper on a typical 3:1 input/output mix ($179 vs $525 a month for 50,000 support chats)
- you generate long outputs in one go — up to 944K tokens (about 707,800 words) per response
- you want the newer model — released 2026-09-02, 11 months after the other
Frequently asked questions
Is Anthropic: Claude Sonnet 4.5 better than Meta: Muse Spark 1.3?
Meta: Muse Spark 1.3 comes out ahead on the data we track: 3 advantages and none for Anthropic: Claude Sonnet 4.5.
Which is cheaper, Anthropic: Claude Sonnet 4.5 or Meta: Muse Spark 1.3?
Meta: Muse Spark 1.3 is cheaper: $2.00 vs $6.00 per 1M tokens at a typical 3:1 input/output mix, 67% less. For 50,000 support conversations a month that is $179 against $525.
How much do Anthropic: Claude Sonnet 4.5 and Meta: Muse Spark 1.3 cost per million tokens?
Anthropic: Claude Sonnet 4.5 costs $3.00 per 1M input tokens and $15.00 per 1M output tokens; Meta: Muse Spark 1.3 costs $1.25 input and $4.25 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Anthropic: Claude Sonnet 4.5 or Meta: Muse Spark 1.3?
Meta: Muse Spark 1.3: 1.0M tokens, about 1,573 pages, against 1M (about 1,500 pages) for Anthropic: Claude Sonnet 4.5.
Do Anthropic: Claude Sonnet 4.5 and Meta: Muse Spark 1.3 support function calling and JSON output?
Tool calling — Anthropic: Claude Sonnet 4.5: yes, Meta: Muse Spark 1.3: yes. JSON-schema structured output — Anthropic: Claude Sonnet 4.5: yes, Meta: Muse Spark 1.3: yes.
Can Anthropic: Claude Sonnet 4.5 or Meta: Muse Spark 1.3 read images?
Yes, both accept image input.
Is Anthropic: Claude Sonnet 4.5 or Meta: Muse Spark 1.3 free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of Anthropic: Claude Sonnet 4.5 and Meta: Muse Spark 1.3?
Anthropic: Claude Sonnet 4.5 can write up to 64K tokens (about 48,000 words) per response; Meta: Muse Spark 1.3 up to 944K (about 707,800 words).
When were Anthropic: Claude Sonnet 4.5 and Meta: Muse Spark 1.3 released?
Anthropic: Claude Sonnet 4.5 was listed on 2025-09-29; Meta: Muse Spark 1.3 on 2026-09-02.
About the two models
Anthropic: Claude Sonnet 4.5
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with...
Full Anthropic: Claude Sonnet 4.5 specs →Meta: Muse Spark 1.3
Muse Spark 1.3 is a multimodal reasoning model from Meta for long-running agentic, multi-agent, and coding workflows. It is designed to keep track of information across extended tasks, work through...
Full Meta: Muse Spark 1.3 specs →