| Signal | LongCat Flash Chat | Delta | Step 3.5 Flash |
|---|---|---|---|
Capabilities | 50 | -17 | |
Benchmarks | 67 | +2 | |
Pricing | 1 | +1 | |
Context window size | 81 | -5 | |
Recency | 96 | -4 | |
Output Capacity | 85 | +65 | |
| Overall Result | 3 wins | of 6 | 3 wins |
9
days higher
6
days
15
days higher
Meituan
StepFun
Step 3.5 Flash saves you $35.00/month
That's $420.00/year compared to LongCat Flash Chat at your current usage level of 100K calls/month.
| Metric | LongCat Flash Chat | Step 3.5 Flash | Winner |
|---|---|---|---|
| Overall Score | 73 | 72 | LongCat Flash Chat |
| Rank | #141 | #144 | LongCat Flash Chat |
| Quality Rank | #141 | #144 | LongCat Flash Chat |
| Adoption Rank | #141 | #144 | LongCat Flash Chat |
| Parameters | -- | -- | -- |
| Context Window | 131K | 262K | Step 3.5 Flash |
| Pricing | $0.20/$0.80/M | $0.10/$0.30/M | -- |
| Signal Scores | |||
| Capabilities | 50 | 67 | Step 3.5 Flash |
| Benchmarks | 67 | 65 | LongCat Flash Chat |
| Pricing | 1 | 0 | LongCat Flash Chat |
| Context window size | 81 | 86 | Step 3.5 Flash |
| Recency | 96 | 100 | Step 3.5 Flash |
| Output Capacity | 85 | 20 | LongCat Flash Chat |
Our composite score (0–100) combines six weighted signals: benchmark performance (25%), pricing efficiency (25%), context window size (15%), model recency (15%), output capacity (10%), and capability versatility (10%). Here's what the scores mean for these two models:
Scores 73/100 (rank #141), placing it in the top 52% of all 290 models tracked.
Scores 72/100 (rank #144), placing it in the top 51% of all 290 models tracked.
With only a 0-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.
Step 3.5 Flash offers 60% better value per quality point. At 1M tokens/day, you'd spend $6.00/month with Step 3.5 Flash vs $15.00/month with LongCat Flash Chat - a $9.00 monthly difference.
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 also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (262K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($0.30/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (73/100) correlates with better nuance, coherence, and style in long-form content
LongCat Flash Chat and Step 3.5 Flash are extremely close in overall performance (only 0.29999999999999716 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
Best for Quality
LongCat Flash Chat
Marginally better benchmark scores; both are excellent
Best for Cost
Step 3.5 Flash
60% lower pricing; better value at scale
Best for Reliability
LongCat Flash Chat
Higher uptime and faster response speeds
Best for Prototyping
LongCat Flash Chat
Stronger community support and better developer experience
Best for Production
LongCat Flash Chat
Wider enterprise adoption and proven at scale
by Meituan
| Capability | LongCat Flash Chat | Step 3.5 Flash |
|---|---|---|
| Vision (Image Input) | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoningdiffers | ||
| Web Search | ||
| Image Output |
Meituan
StepFun
Step 3.5 Flash saves you $0.7800/month
That's 59% cheaper than LongCat Flash Chat 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 | LongCat Flash Chat | Step 3.5 Flash |
|---|---|---|
| Context Window | 131K | 262K |
| Max Output Tokens | 131,072 | -- |
| Open Source | Yes | Yes |
| Created | Sep 9, 2025 | Jan 29, 2026 |
LongCat Flash Chat scores 73/100 (rank #141) compared to Step 3.5 Flash's 72/100 (rank #144), giving it a 0-point advantage. LongCat Flash Chat is the stronger overall choice, though Step 3.5 Flash may excel in specific areas like cost efficiency.
LongCat Flash Chat is ranked #141 and Step 3.5 Flash is ranked #144 out of 290+ AI models. Rankings use a composite score combining benchmark performance (25%), pricing (25%), context window (15%), recency (15%), output capacity (10%), and versatility (10%). Scores update hourly.
Step 3.5 Flash is cheaper at $0.30/M output tokens vs LongCat Flash Chat's $0.80/M output tokens - 2.7x more expensive. Input token pricing: LongCat Flash Chat at $0.20/M vs Step 3.5 Flash at $0.10/M.
Step 3.5 Flash has a larger context window of 262,144 tokens compared to LongCat Flash Chat's 131,072 tokens. A larger context window means the model can process longer documents and conversations.