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Relace vs StepFun
StepFun makes general multimodal models; Relace makes code-apply and search tools for coding agents. Step 3.7 Flash could drive an agent that Relace speeds up.
By The Subconscious Team · Updated
Relace vs StepFun: key differences
These are not substitutes. StepFun is a Shanghai lab whose Step 3.7 Flash is a 198B mixture-of-experts vision-language model with 11B active parameters, 256K context, tool use and structured outputs, priced at $0.20 in and $1.15 out and released under Apache 2.0. Relace hosts a few open models like DeepSeek V4.1 Flash and GLM 5.3, but no StepFun models, and its own models are tools. It sells small models for coding-agent chores: relace-apply-3 merges edits at about 10,000 tokens per second with a 128K cap, agentic search explores large codebases in parallel, and compaction runs at 50,000 tokens per second.
A budget coding agent could combine them, with Step 3.7 Flash planning and writing edits, possibly working from screenshots thanks to its image input, and Relace applying the edits and fetching relevant code. Step 3.7 Flash's 256K window, or Step 5 Preview's 1M, covers inputs that exceed Relace's 128K limit. Deployment differs too. Relace offers hosted or self-hosted options, while StepFun's first-party inference is China-hosted with thin Western support, though its open weights run on vLLM and SGLang. StepFun also trails frontier models on hard multimodal reasoning.
What Relace and StepFun do
Relace
Relace started out training small, fast models that act as tools for coding agents, and by October 2026 its homepage led with open-model inference instead. It says it served 30 trillion tokens in the 30 days to late October and ranks among the top providers on OpenRouter. The hosted catalog covers DeepSeek V4 Pro, V4 Flash and V4.1 Flash, Kimi K3, GLM 5.3, GLM 5.3 Flash and GLM 5.2 over OpenAI and Anthropic compatible APIs, billed per token with no subscription. Prices run from $0.07 in and $0.14 out per million tokens on DeepSeek V4 Flash to $2.00 in and $14.00 out on Kimi K3, and Relace says it reprices often.
Example models: DeepSeek V4.1 Flash, Kimi K3, GLM 5.3, relace-apply-3
Full Relace profileStepFun
StepFun is a Shanghai AI lab known for efficient multimodal models, with a mix of proprietary API models and open-weight releases. In September 2026 it launched Step 5 Preview, its new flagship for agentic work: a 600B-total, 27B-active mixture-of-experts model with 1M context and text and image input, which Artificial Analysis scores level with Kimi K3. It costs $1.00 in and $2.70 out per million tokens, and its weights followed on Hugging Face in mid-October under the custom StepFun Model License 1.0, which allows commercial use with restrictions. Its cheaper workhorse, Step 3.7 Flash, came out in May 2026 as a 198B mixture-of-experts vision-language model with only 11B active parameters. It has 256K context, selectable reasoning levels, tool use and structured outputs, and it ships under Apache 2.0. StepFun's own API prices it at $0.20 in and $1.15 out per million tokens, and OpenRouter carries it too.
Example models: Step 5 Preview, Step 3.7 Flash
Full StepFun profileShould you choose Relace or StepFun?
Relace vs StepFun at a glance
| Attribute | Relace | StepFun |
|---|---|---|
| Model access | Open weights, plus specialist coding models | Open weights (Apache 2.0 or StepFun license) and API models |
| Flagship models | DeepSeek V4.1 Flash, Kimi K3, GLM 5.3, relace-apply-3 | Step 5 Preview, Step 3.7 Flash |
| Speed | ~10,000 tok/s apply | ~128 tok/s on Step 3.7 Flash |
| Price | $0.07 in, $0.50 out (DeepSeek V4.1 Flash) | $0.20 in, $1.15 out (Step 3.7 Flash) |
| Customization | Unknown | Open weights to fine-tune |
| Deployment | Hosted API, OpenRouter or self-hosted | First-party API, OpenRouter |
| Long context | 128K on apply; varies by open model | Up to 1M (Step 5 Preview); 256K on Step 3.7 Flash |
Frequently asked questions
What is the difference between Relace and StepFun?
StepFun makes general multimodal models; Relace makes code-apply and search tools for coding agents. Step 3.7 Flash could drive an agent that Relace speeds up.
When should I choose Relace over StepFun?
Fast merges of edit snippets; Codebase search for PR review and CI; Self-hosted utility models.
When should I choose StepFun over Relace?
A cheap, self-hostable main model for agents; Reading screenshots and video inside agents; Contexts up to 256K tokens.
Is Relace or StepFun cheaper?
Relace: $0.07 in, $0.50 out (DeepSeek V4.1 Flash). StepFun: $0.20 in, $1.15 out (Step 3.7 Flash). The cheaper choice depends on the model and workload.
Which has more context, Relace or StepFun?
Relace: 128K on apply; varies by open model. StepFun: Up to 1M (Step 5 Preview); 256K on Step 3.7 Flash.
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Running long-horizon agents?
If your agents run past 200K tokens, compare both against Subconscious. Our inference stack treats a long-horizon trace as the primary workload, so speed, cost, and accuracy hold up deep into the trace.