Seed 1.8 vs Step 3.7 Flash
Seed 1.8 and Step 3.7 Flash are closely matched at 34.2 and 30.2 on the LLM Stats Score. Step 3.7 Flash is 1.6x cheaper per token.
ByteDance · StepFun · Updated for 2026
Which is better?
Seed 1.8 and Step 3.7 Flash are closely matched on the overall LLM Stats Score at 34.2 and 30.2.
In the 1 individual benchmarks reported for both models, Step 3.7 Flash wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, Step 3.7 Flash is roughly 1.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Step 3.7 Flash also accepts a larger context window (262,144 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Seed 1.8
- you want predictable pricing at $0.25/M input and $2.00/M output
Choose Step 3.7 Flash
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- cost matters — it's about 1.6x cheaper per token
- you process long inputs — it offers a 262,144 token context window
- you want the most recent training data — it shipped Jun 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Individual benchmarks
57 reported for Seed 1.8 · 4 for Step 3.7 Flash
Seed 1.8 outperforms in 0 benchmarks, while Step 3.7 Flash is better at 1 benchmark (Humanity's Last Exam (with tools, text-only)).
Step 3.7 Flash significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Seed 1.8 ($0.25/1M tokens) is 1.3x more expensive than Step 3.7 Flash ($0.20/1M tokens).
For output processing, Seed 1.8 ($2.00/1M tokens) is 1.7x more expensive than Step 3.7 Flash ($1.15/1M tokens).
In conclusion, Seed 1.8 is more expensive than Step 3.7 Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Step 3.7 Flash accepts 262,144 input tokens compared to Seed 1.8's 256,000 tokens. Step 3.7 Flash can generate longer responses up to 262,144 tokens, while Seed 1.8 is limited to 256,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Seed 1.8 and Step 3.7 Flash support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Seed 1.8
Step 3.7 Flash
License
Usage and distribution terms
Seed 1.8 is licensed under a proprietary license, while Step 3.7 Flash uses Apache 2.0.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Apache 2.0
Open weights
Release Timeline
When each model was launched
Seed 1.8 was released on 2026-02-17, while Step 3.7 Flash was released on 2026-06-10.
Step 3.7 Flash is 4 months newer than Seed 1.8.
Feb 17, 2026
7 months ago
Jun 10, 2026
3 months ago
3mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Seed 1.8 is available from DeepInfra. Step 3.7 Flash is available from DeepInfra.
Seed 1.8
Step 3.7 Flash
Outputs Comparison
Judge for yourself.
Run your own prompts against Seed 1.8 and Step 3.7 Flash side-by-side, then vote on the output you prefer.
FAQ
Common questions about Seed 1.8 vs Step 3.7 Flash.