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MiniMax-M3 vs Kimi K3.1 Pro

How MiniMax-M3 (MiniMax, June 2026) and Kimi K3.1 Pro (Moonshot AI, October 2026) are built, drawn on the same November 2026 blueprint. They make different choices on 12 of 27 components. Select a component in either diagram to find it in the table.

--- frontier-llm@2026-11+++ minimax-m3@2026-06+0~4−4

MiniMax-M3

MiniMax, June 2026, 427.0B total, 23.5B active

Text · code · tool outputText · code · tool outputImages · video · audioImages · video · audioByte-level BPE tokenizer — 128K–262K vocabByte-level BPE tokenizer128K–262K vocabVision / audio encoder — native ViT or encoder-free patchesVision / audio encodernative ViT or encoder-free patchesToken embedding — media embeds spliced in placeToken embeddingmedia embeds spliced in placeEngram n-gram memory — hashed 2–4-gram lookup (V4.1)Engram n-gram memoryhashed 2–4-gram lookup (V4.1)Single residual stream — Residual & normSingle residual streamResidual & normRMSNorm — pre-normRMSNormpre-normQK-Norm — per-head RMSNorm on q, kQK-Normper-head RMSNorm on q, kPartial RoPE / NoPE — rotate 64 dims, or nonePartial RoPE / NoPErotate 64 dims, or noneGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersFull grouped-query attention in blocks 0–2 — AttentionFull grouped-query attention…AttentionMiniMax Sparse Attention (MSA) — AttentionMiniMax Sparse Attention (MS…AttentionSliding-window attention — local · 128–1,024-token windowSliding-window attentionlocal · 128–1,024-token windowOutput gate + sink — σ(x·W_g) ⊙ o · learnable sinkOutput gate + sinkσ(x·W_g) ⊙ o · learnable sink⊕ residual⊕residualRMSNorm — pre-normRMSNormpre-normMoE router — σ / √softplus · bias balancingMoE routerσ / √softplus · bias balancingRouted experts — top-6–22 of 256–896 · SwiGLURouted expertstop-6–22 of 256–896 · SwiGLUShared expert — 1–2 · always activeShared expert1–2 · always active⊕ residual⊕residualFinal RMSNormFinal RMSNormLM head — untied · vocab logitsLM headuntied · vocab logitsMTP module(s) — predict t+2 … t+kMTP module(s)predict t+2 … t+kNext-token logitsNext-token logitsDraft tokensDraft tokensMuon optimizer — Newton–Schulz · QK-Clip · per-headMuon optimizerNewton–Schulz · QK-Clip · per-headBF16 weights plus an official MXFP8 checkpoint — Training & inferenceBF16 weights plus an official MXFP8 ch…Training & inferenceLong-context extension — staged 4K → 1M · YaRNLong-context extensionstaged 4K → 1M · YaRNRL with verifiable rewards — GRPO family · async agentic RLRL with verifiable rewardsGRPO family · async agentic RLOn-policy distillation — reverse KL to specialist teachersOn-policy distillationreverse KL to specialist teachersSpeculative decoding — MTP self-drafting · DSparkSpeculative decodingMTP self-drafting · DSparkKV-cache compression — FP4 KV · cross-layer reuse · SSDKV-cache compressionFP4 KV · cross-layer reuse · SSD
AttentionMixture of expertsResidual & normInput & outputTraining & inferenceData flowResidual / skipAddedReplacedNot usedNot disclosed

--- frontier-llm@2026-11+++ kimi-k3-1-pro@2026-10+0~5−2

Kimi K3.1 Pro

Moonshot AI, October 2026, 2.8T total, 104B active

Text · code · tool outputText · code · tool outputImages · video · audioImages · video · audioByte-level BPE tokenizer — 128K–262K vocabByte-level BPE tokenizer128K–262K vocabVision / audio encoder — native ViT or encoder-free patchesVision / audio encodernative ViT or encoder-free patchesToken embedding — media embeds spliced in placeToken embeddingmedia embeds spliced in placeEngram n-gram memory — hashed 2–4-gram lookup (V4.1)Engram n-gram memoryhashed 2–4-gram lookup (V4.1)Block Attention Residuals (AttnRes) — Residual & normBlock Attention Residuals (AttnRes)Residual & normRMSNorm — pre-normRMSNormpre-normQK-Clip and normalized latents; LayerNorm on the indexer key — Residual & normQK-Clip and normalized latents; LayerN…Residual & normPartial RoPE / NoPE — rotate 64 dims, or nonePartial RoPE / NoPErotate 64 dims, or noneGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersLatent attention (MLA) — global · GQA in many modelsLatent attention (MLA)global · GQA in many modelsSparse / compressed attn — DSA indexer · CSA / HCASparse / compressed attnDSA indexer · CSA / HCASliding-window attention — local · 128–1,024-token windowSliding-window attentionlocal · 128–1,024-token windowOutput gate + sink — σ(x·W_g) ⊙ o · learnable sinkOutput gate + sinkσ(x·W_g) ⊙ o · learnable sink⊕ residual⊕residualRMSNorm — pre-normRMSNormpre-normSigmoid router with Quantile Balancing — Mixture of expertsSigmoid router with Quantile BalancingMixture of expertsStable LatentMoE routed experts (SiTU-GLU) — Mixture of expertsStable LatentMoE routed experts (SiTU-…Mixture of expertsShared expert — 1–2 · always activeShared expert1–2 · always active⊕ residual⊕residualFinal RMSNormFinal RMSNormLM head — untied · vocab logitsLM headuntied · vocab logitsNo MTP layer in the open checkpoint — Input & outputNo MTP layer in the open checkpointInput & outputNext-token logitsNext-token logitsDraft tokensDraft tokensMuon optimizer — Newton–Schulz · QK-Clip · per-headMuon optimizerNewton–Schulz · QK-Clip · per-headFP8 → FP4 training — block-scaled FP8 · MXFP4/NVFP4 QATFP8 → FP4 trainingblock-scaled FP8 · MXFP4/NVFP4 QATLong-context extension — staged 4K → 1M · YaRNLong-context extensionstaged 4K → 1M · YaRNRL with verifiable rewards — GRPO family · async agentic RLRL with verifiable rewardsGRPO family · async agentic RLOn-policy distillation — reverse KL to specialist teachersOn-policy distillationreverse KL to specialist teachersSpeculative decoding — MTP self-drafting · DSparkSpeculative decodingMTP self-drafting · DSparkKV-cache compression — FP4 KV · cross-layer reuse · SSDKV-cache compressionFP4 KV · cross-layer reuse · SSD
AttentionMixture of expertsResidual & normInput & outputTraining & inferenceData flowResidual / skipAddedReplacedNot usedNot disclosed

Component by component

MiniMax-M3 and Kimi K3.1 Pro differ on 12 of 27 components.

Blueprint componentMiniMax-M3Kimi K3.1 Pro

Single residual streamOne d = 6,144 residual stream with pre-norm sublayers; no hyper-connections.

Block Attention Residuals (AttnRes)Each sublayer reads a softmax-weighted mix of the embedding and earlier 12-layer block summaries, as in K3.

Same as the blueprintPer-head Gemma-style RMSNorm (ε = 1e-6) on q and k before RoPE, with one 128-dim gain shared by all 64 query heads and one by the 4 key heads; the indexer's queries and key get their own. This replaces M2's layer-wide norm over the concatenated projections (qk_norm_type per_layer → per_head), so head-sharded tensor parallelism no longer needs a cross-rank reduction for it.

QK-Clip and normalized latents; LayerNorm on the indexer keyNo per-head QK-Norm: K2-style weight clipping for MLA, L2-normalized q/k in KDA, a LayerNorm on the DSA indexer key.

Not used

Same as the blueprintKDA in 69 of 93 layers (three of every four, starting at layer 1), unchanged from K3: 96 heads with 128-dim q, k, v and a 128 × 128 state per head; short conv (kernel 4) + Swish on q, k, v; L2-normalized q, k. The log-decay is bounded as g = −5·σ(eᴬ·z), which keeps 16-token-tile rescaling inside BF16 range so every intra-chunk tile runs as a tensor-core matmul.

Full grouped-query attention in blocks 0–2The first three blocks attend over the whole context: 64 query heads share 4 KV heads of dim 128; no indexer, gate or sink.

Same as the blueprintGated MLA in the same 24 layers as K3 (4, 8, …, 92 plus 93), every projection the same shape: 96 heads, queries via a 1,536-dim latent, keys and values from a 512-dim latent plus a 64-dim shared key slot (576 cached values per token per layer), q/k head dim 192, v head dim 128. The difference is the key set: each query now attends only to the 2,048 tokens its layer's DSA indexer selects, not the full prefix.

MiniMax Sparse Attention (MSA)Per GQA group, a 2-projection indexer picks the top 16 of 128-token KV blocks; exact softmax over ≤ 2,048 keys, in 57 of 60 layers.

Same as the blueprintNew in K3.1: a DSA lightning indexer in each of the 24 MLA layers, each with its own weights (vLLM: no index sharing). 32 heads × 128 dims; queries from the 1,536-dim query latent (1,536 → 4,096), one shared 128-dim key from the hidden state with a LayerNorm, per-head weights from a 7,168 → 32 projection. Scores I = Σₕ wₕ·ReLU(qₕ·k) pick the top 2,048 tokens per query. 7.44M BF16 parameters per layer. DeepSeek-V3.2's indexer has 64 heads. How it was trained is unpublished.

Not used

Same as the blueprintBoth mixers keep K3's input-dependent, full-rank, channel-wise sigmoid gate σ(W_g·x), W_g: 7,168 → 12,288 (96 × 128). In gated DSA it multiplies the sparse MLA output; in KDA it multiplies the head-wise RMSNorm of the recurrent output. No sink logits.

Same as the blueprintAn FP32 linear router scores 128 experts with sigmoids. A per-expert bias (e_score_correction_bias, FP32) is added only to choose the top 4, the 4 unbiased scores are renormalized to sum to 1, and the routed output is multiplied by 2.0 (routed_scaling_factor) before the shared expert is added. MiniMax has not described how M3's biases are updated or whether an auxiliary balance loss is used.

Sigmoid router with Quantile BalancingSigmoid scores pick 16 of 896 experts; each expert's selection bias is set every step from a quantile of routing margins.

Same as the blueprint128 experts of intermediate size 3,072, top-4 active, in blocks 3–59 (M2: 256 of width 1,536, top-8). Blocks 0–2 use a dense MLP of width 12,288 instead. Every FFN uses gpt-oss's clamped SwiGLU: gate clamped at 7, linear branch to ±7, output (x_lin + 1) · x_glu · σ(1.702 · x_glu). Routed experts hold 413.1B of the 427.0B parameters.

Stable LatentMoE routed experts (SiTU-GLU)896 SiTU-GLU experts run in a 3,584-dim latent (half of d); 16 fire per token; an RMSNorm precedes the up-projection.

Same as the blueprintNot in the released weights: neither the BF16 nor the MXFP8 checkpoint contains MTP tensors, and the Transformers port discards mtp.* keys on load. The configs disagree on the module count (num_mtp_modules = 7 with num_nextn_predict_layers = 1 in the BF16 config, 1 in the MXFP8 config), and MiniMax has not described M3's MTP. M2 used 3 modules.

No MTP layer in the open checkpointThe checkpoint ships without MTP weights; Moonshot has not described a K3.1 drafter, so serving engines bring their own.

Not disclosed

Same as the blueprintInherited from K3's pretraining: Per-Head Muon, which orthogonalizes each head's block of the Q, K and V momentum separately, plus Kimi K2's weight clipping, a cosine LR schedule with 1% linear warmup and weight decay 0.1. Moonshot has not said which optimizer trained the new indexer or K3.1's own training stages.

BF16 weights plus an official MXFP8 checkpointBF16 release with an FP32 router; MiniMax-M3-MXFP8 stores the text stack's linears as E4M3 with one 8-bit scale per 32 weights.

Same as the blueprintRouted-expert weights in MXFP4 (group 32, 8-bit shared scale) with MXFP8 activations under quantization-aware training, as in K3. Everything else is BF16, including the new indexer, whose 178.5M parameters are the only change in the per-dtype parameter counts from K3. vLLM and SGLang cache MLA latents and indexer keys in FP8 by default.

Not disclosed

Same as the blueprintMoonshot has not described speculative decoding for K3.1. The vLLM recipe drafts with Inferact's 5-layer DSpark preview model and SGLang with RadixArk's DFlash2 preview (block 8). Neither drafter comes from Moonshot, and Moonshot has not explained the 2–3× speed of the hosted Highspeed variant.

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