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DeepSeek · Open weights

DeepSeek V3.1 Terminus

Added Aug 2, 2025Open weights

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Use in the app

DeepSeek-V3.1-Terminus. The latest update builds on V3.1's strengths while addressing key user feedback. Language consistency improvements (fewer CN/EN mix-ups, no random chars), stronger Code Agent & Search Agent performance, and more stable, reliable outputs across benchmarks. FP8.

  • Tools
  • Structured output
Input
Text
Output
Text
Discovery tier
Open weights

Pricing

USD per 1M tokens
Input
$0.25
Output
$0.70

Reference prices as published by the model provider. API example

Specifications

Context window
128K
Max output
65.5K
Average output (7 days)
364 tokens
Longer than 37% of 465 models

Side by side

DeepSeek V3.1 Terminus compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

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DeepSeek V3.1 TerminusDeepSeekThis modelGPT 5.1OpenAIRemove
ProviderDeepSeekOpenAI
Discovery tierOpen weightsFrontier
AddedAug 2, 2025Nov 13, 2025
Limits
Context window128K400KBest
Max output65.54K128KBest
Average output364 tokens294 tokens
Pricing, USD per 1M tokens
Input$0.25Best$1.25
Output$0.70Best$10.00
Cache read—$0.13
Performance
Throughput21.0 tok/s—
Time to first token2.5 s—
Request success (24h)100.0%100.0%
Benchmark indexes
Intelligence Index13.9Best13.3
Math Index53.7Best38.0
Capabilities
ReasoningNoYes
ToolsYesYes
VisionNoYes
Structured outputYesYes
PDF inputNoYes
Reasoning effort—none, low, medium, high

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

  • DeepSeek V3.1 Terminus
  • GPT 5.1

Intelligence Index

  • DeepSeek V3.1 Terminus13.9
  • GPT 5.113.3

DeepSeek V3.1 Terminus: Better than 34% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Math Index

    Composite of the math evaluations

    • DeepSeek V3.1 Terminus: 53.7Top
    • GPT 5.1: 38.0

Document reasoning

  • AA-LCRv1.1

    Reasoning across long documents

    • DeepSeek V3.1 Terminus: 45.3%Top
    • GPT 5.1: 45.0%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • DeepSeek V3.1 Terminus: 8.7%Top
    • GPT 5.1: 5.3%

  • GPQA Diamond

    Graduate-level science questions

    • DeepSeek V3.1 Terminus: 75.1%Top
    • GPT 5.1: 64.3%

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • DeepSeek V3.1 Terminus: 83.6%Top
    • GPT 5.1: 80.1%

  • IFBench

    Following precise output instructions

    • DeepSeek V3.1 Terminus: 41.2%
    • GPT 5.1: 43.2%Top

Coding

  • LiveCodeBench

    Recent competitive programming problems

    • DeepSeek V3.1 Terminus: 52.9%Top
    • GPT 5.1: 49.4%

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • DeepSeek V3.1 Terminus: 53.7%Top
    • GPT 5.1: 38.0%

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • DeepSeek V3.1 Terminus: 31.8%Top
    • GPT 5.1: 22.7%

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • DeepSeek V3.1 Terminus: 37.1%
    • GPT 5.1: 46.5%Top

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • DeepSeek V3.1 Terminus: 45.3%Top
    • GPT 5.1: 45.0%

Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Throughput
21.0 tok/s
Faster than 12% of 250 models
Time to first token
2.5 s
Quicker than 68% of 250 models
Prompt cache hits
72.2%
Request success (24h)
100.0%
Reliable

Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.

Hourly request success · last 72 hoursLowest hour 98.0%
  • Healthy (98% or more)
  • Degraded (90–98%)
  • Down (under 90%)
  • No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-ai/DeepSeek-V3.1-Terminus",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="deepseek-ai/DeepSeek-V3.1-Terminus",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

DeepSeek

Other DeepSeek models, starting with the same family.