DeepSeek · Open weights
DeepSeek V3.1 Terminus
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.
| DeepSeek V3.1 TerminusDeepSeekThis model | DeepSeek V4.1 Flash 1017DeepSeekRemove | |
|---|---|---|
| Provider | DeepSeek | DeepSeek |
| Discovery tier | Open weights | Open weights |
| Added | Aug 2, 2025 | Oct 17, 2026 |
| Limits | ||
| Context window | 128K | 1.05MBest |
| Max output | 65.54K | 393.22KBest |
| Average output | 364 tokens | 465 tokens |
| Pricing, USD per 1M tokens | ||
| Input | $0.25 | $0.10Best |
| Output | $0.70 | $0.60Best |
| Cache read | — | $0.003 |
| Performance | ||
| Throughput | 21.0 tok/s | 154.0 tok/sBest |
| Time to first token | 2.5 s | 2.2 sBest |
| Request success (24h) | 100.0%Best | 99.7% |
| Benchmark indexes | ||
| Intelligence Index | 13.9 | 24.7Best |
| Math Index | 53.7 | — |
| Capabilities | ||
| Reasoning | No | Yes |
| Tools | Yes | Yes |
| Vision | No | Yes |
| Structured output | Yes | Yes |
| Reasoning effort | — | none, low, high, max |
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
- DeepSeek V3.1 Terminus
- DeepSeek V4.1 Flash 1017
Intelligence Index
- DeepSeek V3.1 Terminus13.9
- DeepSeek V4.1 Flash 101724.7
DeepSeek V3.1 Terminus: Better than 34% of 326 scored models
Indexes
Math Index
Composite of the math evaluations
- DeepSeek V3.1 Terminus: 53.7
- DeepSeek V4.1 Flash 1017: —
Agentic work
AutomationBench-AA
Workflow automation, penalized for guardrail violations
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 47.8%
AutomationBench-AA tasks completed
Workflows finished end to end without a guardrail violation
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 14.2%
AA-Briefcasev1.1
Agentic knowledge work, rated head to head
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 1,118 Elo
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 1,340 Elo
Document reasoning
GDP.pdf
Professional reasoning over PDF documents, all-pass rate
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 3.8%
AA-LCRv1.1
Reasoning across long documents
- DeepSeek V3.1 Terminus: 45.3%
- DeepSeek V4.1 Flash 1017: 55.3%Top
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- DeepSeek V3.1 Terminus: 8.7%
- DeepSeek V4.1 Flash 1017: 10.8%Top
GPQA Diamond
Graduate-level science questions
- DeepSeek V3.1 Terminus: 75.1%
- DeepSeek V4.1 Flash 1017: —
MMLU-Pro
Multi-subject knowledge and reasoning
- DeepSeek V3.1 Terminus: 83.6%
- DeepSeek V4.1 Flash 1017: —
IFBench
Following precise output instructions
- DeepSeek V3.1 Terminus: 41.2%
- DeepSeek V4.1 Flash 1017: —
Coding
Terminal-Benchv4.0
Practical software engineering in a terminal
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 5.6%
SciCode
Scientific computing in Python
- DeepSeek V3.1 Terminus: —
- DeepSeek V4.1 Flash 1017: 35.5%
LiveCodeBench
Recent competitive programming problems
- DeepSeek V3.1 Terminus: 52.9%
- DeepSeek V4.1 Flash 1017: —
Math
AIME 2025
Competition mathematics, 2025 problems
- DeepSeek V3.1 Terminus: 53.7%
- DeepSeek V4.1 Flash 1017: —
Legacy evaluations
Terminal-Bench Hard
Earlier terminal task suite
- DeepSeek V3.1 Terminus: 31.8%
- DeepSeek V4.1 Flash 1017: —
τ²-Bench Telecom
Tool use in a customer-support simulation
- DeepSeek V3.1 Terminus: 37.1%
- DeepSeek V4.1 Flash 1017: —
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- DeepSeek V3.1 Terminus: 45.3%
- DeepSeek V4.1 Flash 1017: 55.3%Top
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- DeepSeek V3.1 Terminus
- DeepSeek V4.1 Flash 1017
| Leaderboard | DeepSeek V3.1 Terminus | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| ARC-AGI-1 | Not in top 20 | #17 · 94.5% |
| ARC-AGI-2 | Not in top 20 | #16 · 78.1% |
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
- DeepSeek V3.1 Terminus
- DeepSeek V4.1 Flash 1017
| Leaderboard | DeepSeek V3.1 Terminus | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| Website | Not in top 20 | #17 · 1300 |
| UI Component | Not in top 20 | #16 · 1301 |
| SVG | Not in top 20 | #18 · 1242 |
| 3D | Not in top 20 | #12 · 1361 |
| ASCII Art | Not in top 20 | #18 · 1221 |
Ranks among Noumen catalog models on Design Arena leaderboards. Only top-20 placements are listed.Design Arena
- DeepSeek V3.1 Terminus
- DeepSeek V4.1 Flash 1017
| Leaderboard | DeepSeek V3.1 Terminus | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| Usage Share | Not in top 20 | #10 · 2.2% |
Ranks among Noumen catalog models on Usage leaderboards. Only top-20 placements are listed.
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.
- 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.
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
Related models
Other DeepSeek models, starting with the same family.