Tested Kimi K3 for Coding [2026] - Dot Net Perls BlogHome<br>Categories<br>Blog<br>Tested Kimi K3 for Coding
Links<br>Updated Jul 18, 2026
Tested Kimi K3 for Coding<br>Jul 18, 2026The new model Kimi K3 was released this week, and it is claimed to be near-frontier level quality similar to Fable and GPT. I decided to try it out and see if it could optimize my Rust program . I felt a less specific task, like "optimize this function somehow" was a good test.<br>Kimi K3I set up Kimi K3 in OpenCode , and made a copy of my program directory so that I could throw away the changes made easily. I directed a prompt to the function I wanted optimized. I had spent a fair amount of time optimizing this function, and I did not seem to be making much progress on my own.<br>Kimi K3 had 2 recommendations , and I decided to have it pursue the SWAR optimization—SIMD Within a Register. With SWAR, a single 64-bit value is treated as 8 eight-bit values—so we can handle 8 u8 values (single-byte) at once.<br>Kimi K3 took about 15 minutes for the task, and it completed it perfectly. I found the optimization sped up the program by 2%. So Kimi K3 both decided on an appropriate optimization, and implemented it with no errors —it seems to me that Kimi K3 could well be a frontier-level model as advertised. It cost about $1 for the tokens on OpenRouter.
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