Mozilla's 91-page report: open-weight AI now only ~4 months behind the frontier
rohanpaul_ai · x · 2026-09-17
Mozilla's new 91-page report finds open-weight AI is only about 4 months behind the frontier — but the economics are inverted.
- By August, 8 of OpenRouter's 10 most-used models by token volume were open-weight, 7 of them Chinese-built; DeepSeek became the first open model to lead the platform in weekly requests.
- Revenue mismatch: open models handled 20% of measured usage but captured only 4% of model-layer revenue, attributed to closed models costing 6x more per call at 90% capability parity. Mozilla notes the revenue data predates its 2026 usage data.
- 79% of surveyed developers use open models, but only 51% of open-model deployments reach production vs 63% for closed models.
- DeepSeek showed major capability jumps may not require fresh pretraining (10 index points, plus 8 from post-training).
- Kimi K3 and Claude Fable 5 showed a 0.72 per-task failure correlation — 'backup' models often fail on the same problems.
Related event: Mozilla Report: Open-Weight Models Now Trail the Frontier by Just ~4 Months(6 posts)→
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