Training

  1. Start of training
  2. Pre-training, 8KKimi K3not stated8KNTPtext and visionMTPallMTP layer
  3. Pre-training, 64KKimi K3not stated64KNTPtext and visionMTPall
  4. Cooldown, 256KKimi K3not stated256KNTPall
  5. Cooldown, 1MKimi K3not stated1MNTPall
  6. SFTKimi K3not statednot statedSFTnot statedMXFP4 experts
  7. Cold-start model
  8. RL: nine expertsKimi K3not stated1MRLKimi K2.5’s, near GRPOnot stated
  9. Nine experts
  10. Where the student starts: not stated
  11. Multi-teacher on-policy distillationKimi K3not statednot statedMOPD9 teachersnot stated
  12. Kimi K3
  • tokens, log scale
  • derived: computed from stated numbers
  • context length
  • all parameters train
  • a part trains
  • all but a part trains
  • NTPdashed: concluded, no source names it
  • not stated by the sources
  • the architecture changes
  • checkpoint
  • checkpoint, weights published
  • a join the sources leave unexplained

Pre-training, 64K

×

Stage · Kimi K3

The same pre-training at a context of 64K, “in a subsequent training phase”.

Context
64K
Objective
next-token prediction over text and visual tokens
Learning rate
Cosine decay with a 1% linear warm-up

Derived

Trained. The report says language and vision are jointly optimized from the start and that the MTP layer is pre-trained, and reports no part as held fixed: that every parameter trains is concluded from that. The report lists no trainable set.

Not disclosed Tokens · Peak and minimum learning rate · Batch · Steps · MTP weight and depth · Number format · Optimizer for non-matrix parameters, the clipping’s rule, momentum · Where the phase begins

All settings8
Objective
One next-token prediction over interleaved visual and text tokens; language and vision trained jointly from the start
Multi-token prediction
One MTP layer with the structure of a backbone block is pre-trained with the model
Optimizer
Per-Head Muon for matrix parameters: the momentum of the attention’s Q, K and V projections is split by head and each head’s block is orthogonalized separately; weight clipping as in Kimi K2
Weight decay
0.1 throughout
Learning rate
Cosine decay with a 1% linear warm-up
Load balancing
Auxiliary-loss-free, by Quantile Balancing: each expert’s bias is set from a quantile of its routing margins
Trainable
Language and vision jointly: the vision encoder, MoonViT-V2, trains from scratch with the model
Context
Extended to 64K in a subsequent training phase
Sources6