Checking Translations

The inlang CLI's check command finds problems in your translations before they ship:

missing and empty translations and forms
missing or unknown variables, and missing markup
missing plural or select forms and selectors
messages your source code no longer uses

npx @inlang/cli check --project ./project.inlang

Checked project.inlang · 7 messages · locales en-US, pt-BR · 2 source files in ./

missing-translation (1)
  welcome_back  pt-BR  no translation

missing-variable (2)
  cart_items  pt-BR  missing {count} (countPlural=other)
  greeting    pt-BR  missing {name}

3 findings
  missing-translation  1
  missing-variable     2

All checks run by default. Pass one or more check flags, such as --missing-translations or --unused-messages, to run only those. See the CLI documentation for every check and option.

check needs @inlang/cli 3.4.0 or later. If your project has an older @inlang/cli in its devDependencies, npx runs that one: update it, or run npx @inlang/cli@latest check.

[!NOTE]inlang validate and inlang lint are deprecated. inlang lint does nothing and exits with 0, so replace it with inlang check in your scripts and CI.

Unused messages

npx @inlang/cli check --project ./project.inlang --unused-messages

Checked project.inlang · 7 messages · locales en-US, pt-BR · 12 source files in ./

unused-message (2)
  legacy_banner
  password_label

2 findings
  unused-message  2

check searches the source files under the project's parent directory for message usages. Pass --source to search only some files or directories, e.g. --source ./src. Git-ignored files, node_modules, Paraglide's compiled output and build tool configs such as vite.config.ts are skipped. See --source for the details.

A message is only reported as unused when every usage in the searched source could be resolved. "Unused" means unused in that source: a message that another repository, or code outside --source, uses can still be reported.

Requirement: m-function matcher 2.3.0 or later

The unused-messages check needs @inlang/plugin-m-function-matcher 2.3.0 or later in the modules of your project.inlang/settings.json. Without it, check skips unused messages and asks you to add it. With an older version, it asks you to update the matcher:

unused-message not checked: The installed @inlang/plugin-m-function-matcher can't analyze usages.
  Unused-message check needs @inlang/plugin-m-function-matcher ≥ 2.3.0, update the module URL in settings.json: https://cdn.jsdelivr.net/npm/@inlang/plugin-m-function-matcher@2.2.6/dist/index.js

Update the version in the module URL (or, for a matcher loaded from node_modules, the installed package):

{
  "modules": [
    "https://cdn.jsdelivr.net/npm/@inlang/plugin-message-format@4.5.0/dist/index.js",
-   "https://cdn.jsdelivr.net/npm/@inlang/plugin-m-function-matcher@2.2.6/dist/index.js"
+   "https://cdn.jsdelivr.net/npm/@inlang/plugin-m-function-matcher@2.3.0/dist/index.js"
  ]
}

Keep the analysis precise

The matcher analyzes JavaScript, TypeScript, JSX, TSX and Svelte files. These usages are fully resolved:

import { m } from "./paraglide/messages.js";

m.welcome_back(); // a call
m["nav.home"](); // a string literal key
const label = m.save_button; // a reference, called later

Building a message key at runtime makes the analysis incomplete, because the analyzer can't know which messages the key refers to:

m[`${fieldName}_label`](); // ❌ dynamic key
m[key](); // ❌ dynamic key
type Key = keyof typeof m; // ❌ can depend on every message

check then names the file, line and reason instead of listing unused messages:

unused-message incomplete: unused messages can't be determined because:
  src/Field.tsx:14:8  m[`${fieldName}_label`]  Dynamic message access cannot be resolved.
  Unused messages are only reported when every usage can be resolved, e.g. m.some_key().

To make it precise, reference each message directly instead of building its key. For example, map values to message functions:

const labels = {
	email: m.email_label,
	phone: m.phone_label,
};

labels[fieldName](); // ✅ every message is referenced directly

This also keeps the messages tree-shakable, as in dynamic messages.

Some constructs make the analysis incomplete in any analyzed file, even when they don't touch messages, because they can load or pass on message modules unseen: re-exports from another module (export * from "./x", export { A } from "./A"), dynamic import(), import.meta.glob, require and eval. Files the matcher can't analyze, such as .vue, .astro, .svx, .mdx or CommonJS files, make it incomplete too. The output names each location, so you can pass --source with the directories that use messages, or accept that unused messages aren't reported for that project.

Run checks in CI

check exits with 1 when it reports findings or project errors, so it fails a CI job without extra configuration. Use --locales to fail only on the locales you ship. Findings that don't belong to a locale, such as unused messages, and project errors are always reported:

# .github/workflows/i18n.yml
name: i18n
on: pull_request
jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 22
      - run: npx @inlang/cli check --project ./project.inlang --locales de,fr

--no-fail exits with 0 even if there are findings, e.g. for a report.
--format json prints the full report for other tools: every finding, the status of each check and the location of each usage that couldn't be analyzed.
A check that couldn't run or couldn't complete, such as unused messages with dynamic keys, is reported but doesn't fail the command.

See exit codes and JSON output in the CLI documentation.

Edit this page on GitHub

File Formats

Monorepo