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GPT OSS 20B vs Mistral Small 4

GPT OSS 20B and Mistral Small 4 are closely matched at 17.4 and 19.5 on the LLM Stats Score. GPT OSS 20B is 3.0x cheaper per token.

OpenAI · Mistral AI · Updated for 2026

Which is better?

GPT OSS 20B and Mistral Small 4 are closely matched on the overall LLM Stats Score at 17.4 and 19.5.

In the 1 individual benchmarks reported for both models, GPT OSS 20B wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, GPT OSS 20B is roughly 3.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Mistral Small 4 also accepts a larger context window (256,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT OSS 20B

  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • cost matters — it's about 3.0x cheaper per token

Choose Mistral Small 4

  • you process long inputs — it offers a 256,000 token context window
  • you want the most recent training data — it shipped Mar 2026

At a glance

The differences that matter most.

GPT OSS 20B
OpenAI
Mistral Small 4
Mistral AI
Core performance indexes
LLM Stats Score
17.4
#197
19.5
#187
Reasoning
15.9
#201
20.3
#174
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$0.05 / M
$0.15 / M
Output price
$0.20 / M
$0.60 / M
Context window
131,072
256,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT OSS 20B
Mistral Small 4
Math
17.4#184
19.3#158
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for GPT OSS 20B · 9 for Mistral Small 4

1 shared

GPT OSS 20B outperforms in 1 benchmarks (GPQA), while Mistral Small 4 is better at 0 benchmarks.

GPT OSS 20B significantly outperforms across most benchmarks.

Sat Aug 29 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT OSS 20B costs less

For input processing, GPT OSS 20B ($0.05/1M tokens) is 3.0x cheaper than Mistral Small 4 ($0.15/1M tokens).

For output processing, GPT OSS 20B ($0.20/1M tokens) is 3.0x cheaper than Mistral Small 4 ($0.60/1M tokens).

In conclusion, Mistral Small 4 is more expensive than GPT OSS 20B.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sat Aug 29 2026 • llm-stats.com
OpenAI
GPT OSS 20B
Input tokens$0.05
Output tokens$0.20
Best providerNovita
Mistral AI
Mistral Small 4
Input tokens$0.15
Output tokens$0.60
Best providerMistral
Notice missing or incorrect data?Start an Issue→

Model Size

Parameter count comparison

98.1B diff

Mistral Small 4 has 98.1B more parameters than GPT OSS 20B, making it 469.4% larger.

OpenAI
GPT OSS 20B
20.9Bparameters
Mistral AI
Mistral Small 4
119.0Bparameters
20.9B
GPT OSS 20B
119.0B
Mistral Small 4

Context Window

Maximum input and output token capacity

Mistral Small 4 accepts 256,000 input tokens compared to GPT OSS 20B's 131,072 tokens. Mistral Small 4 can generate longer responses up to 256,000 tokens, while GPT OSS 20B is limited to 32,768 tokens.

OpenAI
GPT OSS 20B
Input131,072 tokens
Output32,768 tokens
Mistral AI
Mistral Small 4
Input256,000 tokens
Output256,000 tokens
Sat Aug 29 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Mistral Small 4 supports multimodal inputs, whereas GPT OSS 20B does not.

Mistral Small 4 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT OSS 20B

Text
Images
Audio
Video

Mistral Small 4

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under Apache 2.0.

Both models share the same licensing terms, providing consistent usage rights.

GPT OSS 20B

Apache 2.0

Open weights

Mistral Small 4

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT OSS 20B was released on 2025-08-05, while Mistral Small 4 was released on 2026-03-16.

Mistral Small 4 is 7 months newer than GPT OSS 20B.

GPT OSS 20B

Aug 5, 2025

1.1 years ago

Mistral Small 4

Mar 16, 2026

5 months ago

7mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

GPT OSS 20B is available from Novita, Fireworks, Groq, OpenAI. Mistral Small 4 is available from Mistral AI.

GPT OSS 20B

novita logo
Novita
Input Price:Input: $0.05/1MOutput Price:Output: $0.20/1M
fireworks logo
Fireworks
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
groq logo
Groq
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M

Mistral Small 4

mistral logo
Mistral
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against GPT OSS 20B and Mistral Small 4 side-by-side, then vote on the output you prefer.

GPT OSS 20B
✓ Preferred
Mistral Small 4
Open in Playground

FAQ

Common questions about GPT OSS 20B vs Mistral Small 4.

Which is better, GPT OSS 20B or Mistral Small 4?

GPT OSS 20B and Mistral Small 4 are closely matched on the LLM Stats Score at 17.4 and 19.5. GPT OSS 20B is made by OpenAI and Mistral Small 4 is made by Mistral AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT OSS 20B compare to Mistral Small 4 in benchmarks?

GPT OSS 20B scores MMLU: 85.3%, CodeForces: 74.3%, GPQA: 71.5%, TAU-bench Retail: 54.8%, HealthBench: 42.5%. Mistral Small 4 scores AIME 2025: 83.8%, MMLU-Pro: 78.0%, AA-LCR: 71.2%, GPQA: 71.2%, LiveCodeBench: 63.6%.

Is GPT OSS 20B cheaper than Mistral Small 4?

GPT OSS 20B is 3.0x cheaper for input tokens. GPT OSS 20B costs $0.05/M input and $0.20/M output via novita. Mistral Small 4 costs $0.15/M input and $0.60/M output via mistral.

What are the context window sizes for GPT OSS 20B and Mistral Small 4?

GPT OSS 20B supports 131K tokens and Mistral Small 4 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT OSS 20B and Mistral Small 4?

Key differences include LLM Stats Score (17.4 vs 19.5), context window (131K vs 256K), input pricing ($0.05 vs $0.15/M), multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT OSS 20B and Mistral Small 4?

GPT OSS 20B is developed by OpenAI and Mistral Small 4 is developed by Mistral AI.

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