Neither wins outright: Google: Gemini 3.5 Flash (batch) is the pick when cost matters at scale, Meta: Muse Spark Open when you need log-probabilities.
| Spec | Google: Gemini 3.5 Flash (batch) | Meta: Muse Spark Open |
|---|---|---|
| Provider | Meta | |
| Input price (per 1M tokens) | $0.75 | $1.25 |
| Output price (per 1M tokens) | $4.50 | $4.25 |
| Blended price (3:1 input/output) | $1.69 | $2.00 |
| Cheaper than … of all models we track | 30% | 25% |
| Context window | 1.0M tokens (~1,573 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 81% | 81% |
| Max output per response | 66K tokens (~49,200 words) | 944K tokens (~707,800 words) |
| Input types | text, image, video, file, audio | text, image, video, file, audio |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-05-19 | 2026-10-15 |
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) | Google: Gemini 3.5 Flash (batch) | Meta: Muse Spark Open | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $146 | $179 | Google: Gemini 3.5 Flash (batch) saves $32.50 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $135 | $193 | Google: Gemini 3.5 Flash (batch) saves $57.50 |
| 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) | $144 | $201 | Google: Gemini 3.5 Flash (batch) saves $57.00 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $87.00 | $126 | Google: Gemini 3.5 Flash (batch) saves $38.50 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $42.00 | $66.75 | Google: Gemini 3.5 Flash (batch) saves $24.75 |
| Capability | Google: Gemini 3.5 Flash (batch) | Meta: Muse Spark Open | 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 | ✓ Yes | ✓ Yes | 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 | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | ✓ Yes | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Neither wins outright: Google: Gemini 3.5 Flash (batch) is the pick when cost matters at scale, Meta: Muse Spark Open when you need log-probabilities. In short: Google: Gemini 3.5 Flash (batch) when cost matters at scale, you need built-in web search; Meta: Muse Spark Open when you need log-probabilities, you generate long outputs in one go, you want the newer model.
Google: Gemini 3.5 Flash (batch) is cheaper: $1.69 vs $2.00 per 1M tokens at a typical 3:1 input/output mix, 16% less. For 50,000 support conversations a month that is $146 against $179.
Google: Gemini 3.5 Flash (batch) costs $0.75 per 1M input tokens and $4.50 per 1M output tokens; Meta: Muse Spark Open costs $1.25 input and $4.25 output. Output tokens are billed separately, so long answers shift the gap.
Both take 1.0M tokens per request — roughly 1,573 pages of text.
Tool calling — Google: Gemini 3.5 Flash (batch): yes, Meta: Muse Spark Open: yes. JSON-schema structured output — Google: Gemini 3.5 Flash (batch): yes, Meta: Muse Spark Open: yes.
Yes, both accept image input.
No free variant is listed for either; both are pay-per-token.
Google: Gemini 3.5 Flash (batch) can write up to 66K tokens (about 49,200 words) per response; Meta: Muse Spark Open up to 944K (about 707,800 words).
Google: Gemini 3.5 Flash (batch) was listed on 2026-05-19; Meta: Muse Spark Open on 2026-10-15.
Gemini 3.5 Flash is Google's high-efficiency multimodal model, bringing near-Pro level coding and reasoning at Flash-tier cost and speed. It is highly optimized for coding proficiency and parallel agentic execution...
Full Google: Gemini 3.5 Flash (batch) specs →Muse Spark Open is a coding-optimized open-weight model. Trained specifically for agentic coding workflows, it delivers higher first-attempt accuracy, reliable tool calling, and deep codebase understanding across the repos developers...
Full Meta: Muse Spark Open specs →