Why high: an exact fingerprint shared with 13 models that declare the same family, without a second signal of a different kind yet.
DeepSeek: DeepSeek V3.1 Terminus is DeepSeek's model, and its measured tokenizer sits in DeepSeek's own signature group alongside its sibling models. Measured models from StepFun carry the same vocabulary, which reads as reuse of DeepSeek's tokenizer line and questions nobody's authorship; they are listed under "Shares this fingerprint" below.
| We checked | What we found | Where it came from |
|---|---|---|
| How it counts tokens | Counts every one of the 50 test strings exactly like 13 other models | tk_73c4f0dc |
| How its API is set up | A combination of settings no other listing in the catalogue uses | api_57c8e44d |
| How much it can read and write | Reads up to 163,840 tokens at onceOpenRouter's listing shows 147,456 output tokens, which is 90% of the context window, the figure it carries where the provider declares no maximum. DeepSeek's own API reference caps max_tokens at 384K, 393,216 tokens, for deepseek-flash and deepseek-v4-pro. | its own listing |
| Whether it thinks before answering | Reasons when asked to | its own listing |
| Who served our requests | Novita | we measured it, 21 August 2026 |
Click a row to open the full comparison.
We sent DeepSeek: DeepSeek V3.1 Terminus fifty short pieces of text and recorded what each one cost it in tokens. The bars below are those costs. Two models built on the same tokenizer produce the same bars; a model built on a different one produces a different set, which is what makes this a fingerprint.
Overhead subtracted: 4 prompt tokens.
DeepSeek-V3.1 Terminus is an update to [DeepSeek V3.1](/deepseek/deepseek-chat-v3.1) that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's...
Supported parameters
frequency_penaltyinclude_reasoninglogit_biasmax_tokensmin_ppresence_penaltyreasoningrepetition_penaltyresponse_formatseedstopstructured_outputstemperaturetool_choicetoolstop_ktop_p
defaults: {"temperature":null,"top_p":null,"frequency_penalty":null}
