GPT-4o mini vs gpt-oss-20b

Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.

GPT-4o mini

OpenAI · Jul 2024

The 2024 budget classic that defined the cheap-LLM tier; GPT-5 nano and mini have since taken its crown.

gpt-oss-20b

OpenAI · Aug 2025

The small gpt-oss variant that runs on a 16GB consumer GPU or laptop — local reasoning for everyone, Apache 2.0 licensed.

The verdict

These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. gpt-oss-20b is about 3.0x cheaper per blended million tokens (3:1 input:output mix). gpt-oss-20b also takes 131K of context versus 128K for GPT-4o mini. And gpt-oss-20b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.

Specs & pricing

GPT-4o minigpt-oss-20b
modhub Index
Input price / 1M$0.15$0.05
Output price / 1M$0.6$0.2
Context window128K131K
Max output16K131K
Open weightsnoyes (Apache 2.0)
Reasoning modelnoyes
Multimodal inputtext, imagetext
Knowledge cutoffOct 2023Jun 2024
ReleasedJul 2024Aug 2025
Example monthly cost*$2.40$0.8

* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.

Frequently asked questions

Which is better, GPT-4o mini or gpt-oss-20b?
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. gpt-oss-20b is about 3.0x cheaper per blended million tokens (3:1 input:output mix). gpt-oss-20b also takes 131K of context versus 128K for GPT-4o mini. And gpt-oss-20b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Which is cheaper, GPT-4o mini or gpt-oss-20b?
GPT-4o mini costs $0.15/$0.6 per million input/output tokens, while gpt-oss-20b costs $0.05/$0.2. For a typical workload of 10M input and 1.5M output tokens per month, that's $2.40 versus $0.8.
Which model is better for coding, GPT-4o mini or gpt-oss-20b?
We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.

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