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Rust vs Go for a CLI Tool: 0.3 MB vs 2.4 MB, and the Build-Time Surprise

The same word-frequency CLI in both languages. Rust’s binary was 8x smaller, the run speed tied, and the build times flipped in a way I did not expect

5 min readOct 28, 2026

Figure 1: The same CLI, built both ways. Rust shipped a 0.3 MB binary to Go’s 2.4 MB, but Go rebuilt in a fraction of the time.

Rust and Go are the two go-to languages for a fast command line tool: one binary, no runtime to install, starts instantly. So which should you reach for?

I wrote the exact same CLI in both: read a text file, count word frequency, print the total and the top 10. Then I measured the three things that actually matter for a CLI: binary size, run speed, and build time. The results were not a clean sweep for either side.

Rust            Go
binary (stripped) 0.30 MB         1.54 MB   (2.36 MB unstripped)
run, 17 MB file   ~0.10 s         ~0.07 s   (a tie in practice)
clean build       2.35 s          2.25 s    (about equal)
rebuild (1 edit)  2.06 s          0.07 s    (Go ~30x faster)

I will be sharing the code, each measurement, and the one tradeoff that explains the build-time gap. Everything ran on an Apple M4 Max, Rust 1.88 and Go 1.27.

Was the Rust rebuild a debug or a release build, and was incremental compilation on? I ask because during the edit loop a lot of people only run cargo check and build the final binary at the end. Knowing which one you timed would tell readers whether the gap hits their day or just their CI.

Rust vs Go for a CLI Tool: 0.3 MB vs 2.4 MB, and the Build-Time Surprise

The same word-frequency CLI in both languages. Rust’s binary was 8x smaller, the run speed tied, and the build times flipped in a way I did not expect

Written by Martin

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