| Signal | Phi 4 | Delta | Step 3.5 Flash (free) |
|---|---|---|---|
Capabilities | 33 | -17 | |
Benchmarks | 73 | +7 | |
Pricing | 100 | 0 | |
Context window size | 67 | -19 | |
Recency | 51 | -49 | |
Output Capacity | 70 | -20 | |
| Overall Result | 1 wins | of 6 | 5 wins |
Score History
66.5
current score
Phi 4
right now
65.8
current score
Microsoft
StepFun
Step 3.5 Flash (free) saves you $13.50/month
That's $162.00/year compared to Phi 4 at your current usage level of 100K calls/month.
| Metric | Phi 4 | Step 3.5 Flash (free) | Winner |
|---|---|---|---|
| Overall Score | 67 | 66 | Phi 4 |
| Rank | #103 | #104 | Phi 4 |
| Quality Rank | #103 | #104 | Phi 4 |
| Adoption Rank | #103 | #104 | Phi 4 |
| Parameters | -- | -- | -- |
| Context Window | 16K | 256K | Step 3.5 Flash (free) |
| Pricing | $0.07/$0.14/M | Free | -- |
| Signal Scores | |||
| Capabilities | 33 | 50 | Step 3.5 Flash (free) |
| Benchmarks | 73 | 66 | Phi 4 |
| Pricing | 100 | 100 | Step 3.5 Flash (free) |
| Context window size | 67 | 86 | Step 3.5 Flash (free) |
| Recency | 51 | 100 | Step 3.5 Flash (free) |
| Output Capacity | 70 | 90 | Step 3.5 Flash (free) |
Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.
Scores 67/100 (rank #103), placing it in the top 65% of all 290 models tracked.
Scores 66/100 (rank #104), placing it in the top 64% of all 290 models tracked.
With only a 1-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.
Both models are priced similarly, so the decision comes down to quality and features rather than cost.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Higher benchmark score (0/100) indicates stronger performance on coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Faster response time (speed score 0/100) is critical for user-facing chat. Step 3.5 Flash (free) also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (256K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($0.00/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (67/100) correlates with better nuance, coherence, and style in long-form content
Phi 4 and Step 3.5 Flash (free) are extremely close in overall performance (only 0.7000000000000028 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
Best for Quality
Phi 4
Marginally better benchmark scores; both are excellent
Best for Cost
Step 3.5 Flash (free)
100% lower pricing; better value at scale
Best for Reliability
Phi 4
Higher uptime and faster response speeds
Best for Prototyping
Phi 4
Stronger community support and better developer experience
Best for Production
Phi 4
Wider enterprise adoption and proven at scale
by Microsoft
| Capability | Phi 4 | Step 3.5 Flash (free) |
|---|---|---|
| Vision (Image Input) | ||
| Function Callingdiffers | ||
| Streaming | ||
| JSON Modediffers | ||
| Reasoningdiffers | ||
| Web Search | ||
| Image Output |
Microsoft
StepFun
Step 3.5 Flash (free) saves you $0.2850/month
That's 100% cheaper than Phi 4 at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | Phi 4 | Step 3.5 Flash (free) |
|---|---|---|
| Context Window | 16K | 256K |
| Max Output Tokens | 16,384 | 256,000 |
| Open Source | Yes | Yes |
| Created | Jan 10, 2025 | Jan 29, 2026 |
Phi 4 scores 67/100 (rank #103) compared to Step 3.5 Flash (free)'s 66/100 (rank #104), giving it a 1-point advantage. Phi 4 is the stronger overall choice, though Step 3.5 Flash (free) may excel in specific areas like cost efficiency.
Phi 4 is ranked #103 and Step 3.5 Flash (free) is ranked #104 out of 290+ AI models. Rankings use a composite score combining benchmark performance (90%) from MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations, with capabilities and context window as tiebreakers (10%). Scores update hourly.
Step 3.5 Flash (free) is cheaper at $0.00/M output tokens vs Phi 4's $0.14/M output tokens - 140.0x more expensive. Input token pricing: Phi 4 at $0.07/M vs Step 3.5 Flash (free) at $0.00/M.
Step 3.5 Flash (free) has a larger context window of 256,000 tokens compared to Phi 4's 16,384 tokens. A larger context window means the model can process longer documents and conversations.