// head_to_head

DeepSeek V4.1 Flash vs gpt-oss-120b

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

DeepSeek V4.1 Flash is the cheaper of the two; neither can be ranked on quality here.

gpt-oss-120b does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

deepseek

DeepSeek V4.1 Flash

Blended / 1M
$0.200
Context
1.0M
Released
Sep 10, 2026
Overall score
81.1
reasoningtool callingimage inputprompt caching

openai

gpt-oss-120b

Blended / 1M
$0.262
Context
131K
Released
Aug 5, 2025
Overall score
Not evaluated
reasoningtool callingprompt caching

Specs and pricing

MetricDeepSeek V4.1 Flashgpt-oss-120b
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

81.1
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.0157
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$0.200win$0.262
Input price / 1M$0.100win$0.150
Output price / 1M$0.500win$0.600
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$0.010win$0.075
Context window1.0Mwin131K
Max output tokens944Kwin66K

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — DeepSeek V4.1 Flash on top, gpt-oss-120b below, both out of 100.

Agentic coding
77.3
Coding
80.0
Reasoning
86.7
Mathematics
93.3
Data analysis
79.3
Language
81.2
Instruction following
70.0

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadDeepSeek V4.1 Flashgpt-oss-120b
Support chatbot

1.2K in / 400 out × 200K requests

$57.52/mo$78.60/mo
RAG assistant

8K in / 600 out × 100K requests

$74.00/mo$126.00/mo
Coding agent

40K in / 4K out × 20K requests

$69.60/mo$126.00/mo
Document extraction

20K in / 1.5K out × 50K requests

$133.00/mo$191.25/mo
Bulk classification

500 in / 20 out × 5M requests

$255.00/mo$397.50/mo
Run these two through the cost calculator

Which should you pick?

You need to fit large documents in one call

DeepSeek V4.1 Flash

Wider context window — 1.0M against 131K.

DeepSeek V4.1 Flash vs gpt-oss-120b FAQ

Which is better, DeepSeek V4.1 Flash or gpt-oss-120b?

DeepSeek V4.1 Flash is the cheaper of the two; neither can be ranked on quality here. gpt-oss-120b does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

Is DeepSeek V4.1 Flash cheaper than gpt-oss-120b?

DeepSeek V4.1 Flash is cheaper. On a 3:1 input:output blend, DeepSeek V4.1 Flash lists at $0.200 per million tokens and gpt-oss-120b at $0.262 — DeepSeek V4.1 Flash is 31% cheaper. Input and output are priced separately — DeepSeek V4.1 Flash charges $0.100 in and $0.500 out, gpt-oss-120b charges $0.150 and $0.600 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Does DeepSeek V4.1 Flash or gpt-oss-120b have a bigger context window?

DeepSeek V4.1 Flash has the larger context window: 1.0M for DeepSeek V4.1 Flash against 131K for gpt-oss-120b. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.

Do DeepSeek V4.1 Flash and gpt-oss-120b support prompt caching?

Both publish a cached-input rate: $0.010 per million for DeepSeek V4.1 Flash and $0.075 for gpt-oss-120b, against full input rates of $0.100 and $0.150. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.