Kimi K3 vs Claude Opus 4.8

Kimi K3 is Moonshot AI's newest and most capable model, released in July 2026. At 2.8 trillion parameters, it's the largest open model anyone has shipped so far, and it can hold about a million tokens in memory at once. That's enough room for an entire codebase or a full stack of long documents in a single chat. It comes in two versions: K3 Max for everyday chat and coding, and K3 Swarm Max, which splits one big job across many copies of the model working in parallel.

Where K3 really earns its keep is coding. It's good at finding its way around large projects, making changes that touch many files, and fixing bugs by reading your actual test results and error logs instead of guessing. You can also share screenshots, diagrams, and error messages as images, and it will answer based on what's actually on the screen.

In early testing, K3 beats Claude Opus 4.8 and GPT-5.5 on several coding tests while costing far less to run. It still sits a step below Claude Fable 5 and GPT-5.6 Sol overall, so for the very hardest questions you may get a better answer from one of those. On Aymo, switching between them takes one click.

Anthropic's flagship is built for work that other models get wrong. Opus 4.8 takes on the hardest coding, the deepest analysis, and writing that has to be right first time. It reads images and documents, holds a very large amount of context at once, and works through problems step by step so you can follow its logic. Slower and more expensive than lighter models, by design.