Llama 4 405B vs o4
Open-weights heavyweight. Self-host or run anywhere. Meanwhile, o4: reasoning model. thinks before it speaks.
Side-by-side
Specs
| Dimension | Llama 4 405B | o4 |
|---|---|---|
| Provider | Meta | OpenAI |
| Released | 2025-07 | 2025-09 |
| Context window | ✓256K | 200K |
| Output max | 16K | ✓100K |
| Input /M | ✓$2.70 | $15.00 |
| Output /M | ✓$2.70 | $60.00 |
| Modalities | text, image | text, image |
| Open weights | ✓yes | no |
Scorecard
Dimension-by-dimension
Llama 4 405B
o4
reasoning
8.0
10.0
coding
8.0
9.0
writing
8.0
7.0
speed
6.0
3.0
value
8.0
5.0
Verdict
Which wins, by use case
| Use case | Winner | Why |
|---|---|---|
| coding | o4 | a coin flip on our weighted coding score |
| writing | Llama 4 405B | a clear edge on our weighted writing score |
| chat | Llama 4 405B | a decisive lead on our weighted chat score |
| agents | o4 | a clear edge on our weighted agents score |
| summarization | Llama 4 405B | a decisive lead on our weighted summarization score |
| translation | Llama 4 405B | a decisive lead on our weighted translation score |
| reasoning | o4 | a decisive lead on our weighted reasoning score |
| research | Llama 4 405B | a coin flip on our weighted research score |
| vision and multimodal | o4 | a coin flip on our weighted vision score |
| Cheapest AI models for bulk workloads | Llama 4 405B | a decisive lead on our weighted cheap-bulk score |
Bottom line
Our take
Pick Llama 4 405B if you need: open weights — self-host, no vendor lock-in.
Pick o4 if you need: state-of-the-art math & science, complex planning.
At a 500M-input / 150M-output monthly volume, Llama 4 405B costs roughly $1755 vs o4 at $16500. Use our calculator to plug in your own numbers.
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