typos

Source code spell checker

Finds and corrects spelling mistakes among source code:

• Fast enough to run on monorepos
• Low false positives so you can run on PRs

Dual-licensed under MIT or Apache 2.0

Documentation

• Installation
• Getting Started
  • False Positives
  • Integrations
    • GitHub Action
    • pre-commit
    • Custom
  • Debugging
• Reference
• FAQ
• Comparison with other spell checkers
• Benchmarks
• Design
• Contribute
• CHANGELOG

Install

Download a pre-built binary (installable via gh-install).

Or use rust to install:

cargo install typos-cli

Getting Started

Most commonly, you'll either want to see what typos are available with

typos

Or have them fixed

typos --write-changes
typos -w

If there is any ambiguity (multiple possible corrections), typos will just report it to the user and move on.

False-positives

Sometimes, what looks like a typo is intentional, like with people's names, acronyms, or localized content.

To mark an identifier or word as valid, add it your _typos.toml by declaring itself as the valid spelling:

[default.extend-identifiers]
# *sigh* this just isn't worth the cost of fixing
AttributeIDSupressMenu = "AttributeIDSupressMenu"

[default.extend-words]
# Don't correct the surname "Teh"
teh = "teh"

For cases like localized content, you can disable spell checking of file contents while still checking the file name:

[type.po]
extend-glob = ["*.po"]
check-file = false

(run typos --type-list to see configured file types)

If you need some more flexibility, you can completely exclude some files from consideration:

[files]
extend-exclude = ["localized/*.po"]

Integrations

• GitHub Actions
• pre-commit

Custom

typos provides several building blocks for custom native integrations

• - reads from stdin, --write-changes will be written to stdout
• --diff to provide a diff
• --format json to get jsonlines with exit code 0 on no errors, code 2 on typos, anything else is an error.

Examples:

# Read file from stdin, write corrected version to stdout
typos - --write-changes
# Creates a diff of what would change
typos dir/file --diff
# Fully programmatic control
typos dir/file --format json

Debugging

You can see what the effective config looks like by running

typos --dump-config -

You can then see how typos is processing your project with

typos --files
typos --identifiers
typos --words

If you need to dig in more, you can enable debug logging with -v

FAQ

Why was ... not corrected?

tl;dr typos doesn't know about it yet

typos maintains a list of known typo corrections to keep the false positive count low so it can safely run unassisted.

This is in contrast to most spell checking UIs people use where there is a known list of valid words. In this case, the spell checker tries to guess your intent by finding the closest-looking word. It then has a gauge for when a word isn't close enough and assumes you know best. The user has the opportunity to verify these corrections and explicitly allow or reject them.

For more on the trade offs of these approaches, see Design.

• To correct it locally, see also our False Positives documentation.
• To contribute your correction, see Contribute