Open-weight models
MiniMax ships M3 — open-weight frontier claims, weights to follow
Cheap, capable, and not quite downloadable yet. The brief on what shipped and what to watch.
The answer
MiniMax launched M3 on 1 June 2026, an open-weight frontier coding model with 1M context.
What happened
On 1 June 2026, Shanghai's MiniMax released M3, billed as the first open-weight model to combine frontier coding, a 1M-token context window and native image/video understanding in a single architecture. The underlying mechanism is MiniMax Sparse Attention (MSA), designed to cut prefill and decoding latency at long contexts — the practical bottleneck for agentic coding tasks. MiniMax reports 59.0% on SWE-Bench Pro, ahead of GPT-5.5 and Gemini 3.1 Pro on that test. Those figures are MiniMax's own.
The money. Launch pricing on OpenRouter: roughly $0.30 input / $1.20 output per million tokens (promotional). That's approximately a tenth of comparable closed-frontier rates — the part of this story that's verifiable on day one, because you can call the API and see the bill.
The catch and what to watch
The weights were not published at launch. MiniMax promised them on Hugging Face within approximately ten days of 1 June. Until they land and independent engineers reproduce the SWE-Bench numbers, the benchmark claims are vendor-reported and the 'open-weight' label is a commitment rather than a fact. Separately, ARC-AGI-2 sits under 12% — a real gap on abstract reasoning that MiniMax reported quietly. Strong on coding and long-context retrieval; weaker on flexible reasoning.
MiniMax describes it as the first open-weight model to combine frontier coding performance, million-token context, and native multimodal capabilities, though independent verification of those claims requires the model weights, which had not been released at launch.
Frequently asked questions
What is MiniMax M3 in one line?
Are the weights out?
What is M3 weak at?
Sources
- MiniMax M3 Open-Weight Coding Model: Frontier Claims, Unverified Benchmarks — Tech Times, 1 June 2026
- MiniMax launches M3, an open-weight frontier model with 1M context — DataNorth, 1 June 2026
- What Is MiniMax M3? The First Open-Weight Frontier Coding Model — Apidog, 2 June 2026