codespell

Find and fix spelling errors in code

TLDR

Check for typos in all text files in the current directory, recursively

$ codespell

Correct all typos found in-place

$ codespell [[-w|--write-changes]]

Skip files with names that match the specified pattern (accepts a comma-separated list of patterns using wildcards)

$ codespell [[-S|--skip]] "[pattern]"

Use a custom dictionary file when checking (--dictionary can be used multiple times)

$ codespell [[-D|--dictionary]] [path/to/file.txt]

Do not check words that are listed in the specified file

$ codespell [[-I|--ignore-words]] [path/to/file.txt]

Do not check the specified words

$ codespell [[-L|--ignore-words-list]] [ignored_word1,ignored_word2,...]

Print 3 lines of [C]ontext around, [B]efore, or [A]fter each match

$ codespell [--context|--before-context|--after-context] 3

Check file names for typos, in addition to file contents

$ codespell [[-f|--check-filenames]]

-h, --help
    show help message and exit

-v, --version
    show version and exit

-q INT, --quiet=INT
    quietness level (0=verbose, 1=normal, 2=errors only)

-s STR, --skip=STR
    comma-separated files/paths to skip

--skip-list=STR
    comma-separated words to skip entirely

-d STR, --disable=STR
    comma-separated checks to disable

-e STR, --enable=STR
    comma-separated checks to enable

-c FILE, --config=FILE
    path to config file

-f FILE, --file-list=FILE
    file listing paths to check

-S DIR, --skip-dir=DIR
    comma-separated directories to skip

-i INT, --ignore-lines=INT
    ignore INT lines of context around errors

-w, --write-changes
    write fixes directly to files

-x STR, --exclude=STR
    comma-separated files/paths to exclude

-C DIR, --check-dir=DIR
    recursively check directory

-L STR, --local-dict=STR
    path to custom dictionary file

--hardcase
    case-sensitive checking

--ignore-words=STR
    comma-separated words to ignore

-D DIR, --dictionary=DIR
    directory with dictionary files

-I FILE, --ignore-file=FILE
    file of words to ignore

-A, --stop-at-first-error
    stop after first error

--check-filenames
    check filenames for misspellings

--check-hidden
    include hidden directories

-j INT, --jobs=INT
    number of parallel jobs

DESCRIPTION

Codespell is a fast, lightweight spell-checking tool optimized for source code, documentation, and commit messages.

Unlike general spell checkers, it handles programming idioms like camelCase identifiers, common typos in strings/comments, and technical terms from large codebases (e.g., Linux kernel, Mozilla).

Key features include: built-in dictionaries for code-specific words; recursive directory scanning; parallel processing with -j; interactive corrections; direct file writes with -w; configurable ignores/excludes; and CI/CD integration.

It reports misspellings with line numbers, suggested fixes, and context, ignoring case by default and filenames unless specified. Widely used in open-source projects for quality gates, reducing embarrassing typos in production code.

(~150 words)

CAVEATS

Python-based (requires Python 3); may false-positive rare technical terms; update dictionaries regularly for accuracy; not a full linter.

INSTALLATION

Via pip: pip install codespell
Debian/Ubuntu: apt install codespell

CONFIG FILE

INI-style ~/.codespellrc or --config; sections for ignores, dictionaries.

DICTIONARIES

Built-in: en, code-us, linux, etc. List via codespell -l; customize with --local-dict.

HISTORY

Created by Lucas De Marchi in 2012 as a Python script. Gained traction in 2016 with Linux kernel adoption for spell-checking patches. Now maintained by community, used in GNOME, Rust, Python projects; version 2.x added parallelization and better configs.