GPT OSS 20B vs Grok-4
Grok-4 leads the LLM Stats Score 33.7 to 18.0. GPT OSS 20B is 104.3x cheaper per token.
OpenAI · xAI · Updated for 2026
Which is better?
Grok-4 leads the overall LLM Stats Score 33.7 to 18.0, ranking #98 overall.
In the 2 individual benchmarks reported for both models, Grok-4 wins 2; this is a narrower head-to-head signal than the composite indexes.
On price, GPT OSS 20B is roughly 104.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-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
- cost matters — it's about 104.3x cheaper per token
- you want the most recent training data — it shipped Aug 2025
- you need open weights you can self-host or fine-tune
Choose Grok-4
- overall performance matters — it scores 33.7 and ranks #98 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 2 of 2 exact shared results
- you process long inputs — it offers a 256,000 token context window
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
7 reported for GPT OSS 20B · 7 for Grok-4
GPT OSS 20B outperforms in 0 benchmarks, while Grok-4 is better at 2 benchmarks (GPQA, Humanity's Last Exam).
Grok-4 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT OSS 20B ($0.03/1M tokens) is 100.0x cheaper than Grok-4 ($3.00/1M tokens).
For output processing, GPT OSS 20B ($0.14/1M tokens) is 107.1x cheaper than Grok-4 ($15.00/1M tokens).
In conclusion, Grok-4 is more expensive than GPT OSS 20B.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4 accepts 256,000 input tokens compared to GPT OSS 20B's 131,072 tokens. GPT OSS 20B can generate longer responses up to 131,072 tokens, while Grok-4 is limited to 8,000 tokens.
Input capabilities
Documented input modalities across available providers
Grok-4 supports multimodal inputs, whereas GPT OSS 20B does not.
Grok-4 can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT OSS 20B
Grok-4
License
Usage and distribution terms
GPT OSS 20B is licensed under Apache 2.0, while Grok-4 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
Apache 2.0
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
GPT OSS 20B was released on 2025-08-05, while Grok-4 was released on 2025-07-09.
GPT OSS 20B is 1 month newer than Grok-4.
Aug 5, 2025
1.1 years ago
3w newerJul 9, 2025
1.2 years ago
Knowledge Cutoff
When training data ends
Grok-4 has a documented knowledge cutoff of 2024-12-31, while GPT OSS 20B's cutoff date is not specified.
We can confirm Grok-4's training data extends to 2024-12-31, but cannot make a direct comparison without GPT OSS 20B's cutoff date.
—
Dec 2024
Provider Availability
GPT OSS 20B is available from DeepInfra, Novita, Fireworks, Groq, OpenAI. Grok-4 is available from xAI.
GPT OSS 20B
Grok-4
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT OSS 20B and Grok-4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT OSS 20B vs Grok-4.