gpt-oss-20b vs Mellum2.1-12B-A2.5B-Thinking-GGUF
Specs, VRAM requirements and download trends — updated 25 October 2026.
openai · A · Open weights
Params
21.5 B
Context
131,072
30d
5.8 M
apache-2.0 · commercial OK
JetBrains · B · Open weights
Params
12.0 B
Context
—
30d
215 K
apache-2.0 · commercial OK
Specification comparison
Differences are highlighted; identical values are muted.
| Specification | gpt-oss-20b | Mellum2.1-12B-A2.5B-Thinking-GGUF |
|---|---|---|
| Deployment | Open weights · also via API | Open weights |
| Parameters | 21.5 B | 12.0 B |
| Architecture | GptOssForCausalLM | — |
| Context length | 131,072 | — |
| Licence | apache-2.0 | apache-2.0 |
| Commercial use | Allowed | Allowed |
| Languages | — | 1 |
| Downloads 30d | 5,764,154 | 214,663 |
| Downloads all time | 105.3 M | 215 K |
| Quantizations on the Hub | SAFETENSORS | GGUF |
| Gated | No | No |
| First seen on the Hub | 2025-08-04 | 2026-10-07 |
| API input price / 1M tokens | $0.018 | not on OpenRouter |
| API output price / 1M tokens | $0.09 | not on OpenRouter |
| Est. cost per 1M input + 1M output tokens | $0.11 | not on OpenRouter |
| Cached input / 1M tokens | $0.009 | not on OpenRouter |
| AA Intelligence Index | 10 | not on OpenRouter |
| AA Coding Index | — | not on OpenRouter |
| AA Agentic Index | — | not on OpenRouter |
| Max output tokens | 32,768 | not on OpenRouter |
| API providers | 10 | not on OpenRouter |
| Tool calling | Yes | not on OpenRouter |
| Reasoning mode | Yes | not on OpenRouter |
API cost
Estimated cost of 1M input + 1M output tokens via OpenRouter
gpt-oss-20b
$0.11
Download trend
Daily snapshots, last 90 days (28 Jul – 25 Oct)
8.6 M152 K
gpt-oss-20b
Mellum2.1-12B-A2.5B-Thinking-GGUF
VRAM side by side
On RTX 4090 · 24 GB · 8K context unless noted
Mellum2.1-12B-A2.5B-Thinking-GGUF · Q4_K_M
11.5 GB / 24 GB
gpt-oss-20b · fp16 @ 128K ctx
82.4 GB / 24 GB