Firefunction V1 vs Phi-4 Reasoning Vision 15B
Firefunction V1 (2024) and Phi-4 Reasoning Vision 15B (2026) are compact production models from Fireworks AI and Microsoft Research. Firefunction V1 ships a 8k-token context window, while Phi-4 Reasoning Vision 15B ships a not-yet-sourced context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing. The goal is to make the tradeoff clear before deeper testing.
Phi-4 Reasoning Vision 15B is safer overall; choose Firefunction V1 when provider fit matters.
Decision scorecard
Local evidence first| Signal | Firefunction V1 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Best for | general production evaluation | multimodal apps |
| Decision fit | General | Vision |
| Context window | 8k | — |
| Cheapest output | $0.50/1M tokens | - |
| Provider routes | 1 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Firefunction V1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Firefunction V1 has broader tracked provider coverage for fallback and procurement flexibility.
- Phi-4 Reasoning Vision 15B uniquely exposes Multimodal in local model data.
- Local decision data tags Phi-4 Reasoning Vision 15B for Vision.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Firefunction V1
$525
Cheapest tracked route/tier: Fireworks AI
Phi-4 Reasoning Vision 15B
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Firefunction V1 and Phi-4 Reasoning Vision 15B; plan for SDK, billing, or endpoint changes.
- Phi-4 Reasoning Vision 15B adds Multimodal in local capability data.
- No overlapping tracked provider route is sourced for Phi-4 Reasoning Vision 15B and Firefunction V1; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Multimodal before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-01-29 | 2026-03-12 |
| Context window | 8k | — |
| Parameters | 46B | 15B |
| Architecture | decoder only | - |
| License | Unknown | Microsoft Research |
| Knowledge cutoff | - | 2025-03 |
Pricing and availability
| Pricing attribute | Firefunction V1 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Input price | $0.50/1M tokens | - |
| Output price | $0.50/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Firefunction V1 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Vision | No | No |
| Multimodal | No | Yes |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on multimodal input: Phi-4 Reasoning Vision 15B. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: Firefunction V1 has $0.50/1M input tokens and Phi-4 Reasoning Vision 15B has no token price sourced yet. Provider availability is 1 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Firefunction V1 when provider fit and broader provider choice are central to the workload. Choose Phi-4 Reasoning Vision 15B when provider fit are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Is Firefunction V1 or Phi-4 Reasoning Vision 15B open source?
Firefunction V1 is listed under Unknown. Phi-4 Reasoning Vision 15B is listed under Microsoft Research. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for multimodal input, Firefunction V1 or Phi-4 Reasoning Vision 15B?
Phi-4 Reasoning Vision 15B has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Firefunction V1 and Phi-4 Reasoning Vision 15B?
Firefunction V1 is available on Fireworks AI. Phi-4 Reasoning Vision 15B is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
When should I pick Firefunction V1 over Phi-4 Reasoning Vision 15B?
Phi-4 Reasoning Vision 15B is safer overall; choose Firefunction V1 when provider fit matters. If your workload also depends on provider fit, start with Firefunction V1; if it depends on provider fit, run the same evaluation with Phi-4 Reasoning Vision 15B.
Continue comparing
Last reviewed: 2026-04-19. Data sourced from public model cards and provider documentation.