Alan Donovan
17 February 2026
The 1.26 release of Go this month includes a completely rewritten go fix subcommand. Go fix uses a suite of algorithms to identify opportunities to improve your code, often by taking advantage of more modern features of the language and library. In this post, we’ll first show you how to use go fix to modernize your Go codebase. Then in the second section we’ll dive into the infrastructure behind it and how it is evolving. Finally, we’ll present the theme of “self-service” analysis tools to help module maintainers and organizations encode their own guidelines and best practices.
Running go fix
The go fix command, like go build and go vet , accepts a set of patterns that denote packages. This command fixes all packages beneath the current directory:
$ go fix ./...
On success, it silently updates your source files. It discards any fix that touches generated files since the appropriate fix in that case is to the logic of the generator itself. We recommend running go fix over your project each time you update your build to a newer Go toolchain release. Since the command may fix hundreds of files, start from a clean git state so that the change consists only of edits from go fix; your code reviewers will thank you.
To preview the changes the above command would have made, use the -diff flag:
$ go fix -diff ./... --- dir/file.go (old) +++ dir/file.go (new) - eq := strings.IndexByte(pair, '=') - result[pair[:eq]] = pair[1+eq:] + before, after, _ := strings.Cut(pair, "=") + result[before] = after …
You can list the available fixers by running this command:
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