I18n Support Plus

Plugin ID: com.ibrahimdans.i18n

IntelliJ IDEA plugin providing i18n support for JavaScript, TypeScript, JSX, TSX, and PHP projects.

Supports i18next, vue-i18n, lingui, react-intl, ngx-translate, svelte-i18n, and i18n-js frameworks with JSON, YAML, and PO/POT translation files.

Highlights unresolved i18n keys, offers navigation from keys to their translation files, provides autocomplete for key names, displays translation values as inline hints, and supports key extraction from plain text strings.

Why this plugin?

On a real i18next/vue-i18n project, your keys and translations live in files your editor treats as dead text — so you keep opening JSON files just to check whether a key exists, in which namespace, and whether it's translated everywhere.

I18n Support Plus turns i18n keys into first-class code symbols.

• See & navigate — inline resolution status (gutter ✅/⚠️/❌), Ctrl+Click to the translation and back, value hints (inlay + folding + hover), autocomplete from your real keys (namespaces included), dynamic/wildcard keys supported.
• Edit safely — extract hardcoded strings (Alt+Enter), rename across all locales and code (Shift+F6), move a key to another namespace (Ctrl+Alt+Shift+M), sort keys alphabetically.
• Stay healthy — tool window with tree/table views grouped by namespace, coverage stats per namespace and locale, Keys Synchronizer (propagate missing keys in bulk), Scan Orphans (find unused keys), CSV export/import, and inspections for empty, duplicate or inconsistent values.

Works with i18next, vue-i18n, lingui, react-intl, ngx-translate, svelte-i18n & i18n-js across JS/TS/JSX/TSX, Vue SFC and PHP, with JSON, YAML and PO/POT files. A setup wizard auto-configures it on first launch.

Supported Frameworks

useTranslation supports both string form (useTranslation('ns')) and array form (useTranslation(['ns1', 'ns2'])). The namespace can also come from an options object (t('key', { ns: 'auth' })) or from the key itself (t('auth:key')).

¹ The | translate pipe is recognised in JSX/TSX and in standalone Angular templates (.html). A template is parsed as Angular only inside an Angular project — a component referencing it through templateUrl, with @angular/core resolvable; outside one the file stays plain HTML and the pipe is inert text.

² .svelte single-file components are analysed as well, provided the Svelte plugin is installed — it is not bundled with IntelliJ Ultimate, and without it a .svelte file is plain text to the IDE. With it, both the <script> block and {…} expressions in the markup are ordinary JavaScript, so keys inside them resolve like any other.

³ i18n-js pluralizes into a nested object ({ one: …, other: … }) rather than through i18next's flat key_one suffixes; such a key is treated as resolved. Its %{count} placeholders are displayed verbatim, as the plugin interprets no interpolation syntax.

Supported Languages

Vue support requires the Vue.js plugin (optional dependency). PHP support requires the PHP plugin (optional dependency).

Translation File Formats

Keys are resolved as nested properties by default (app.header.title walks three levels). Projects storing flat ids — one property per key, as react-intl / FormatJS usually do — should enable Treat keys as flat in Settings → Tools → i18n Support Plus Configuration. The setting turns off key-separator splitting and namespace parsing altogether, so the whole id is looked up as a single property and translation files are located through the default namespace.

Features

Setup Wizard

On first launch, a wizard guides you through configuration in 3 steps:

1. Framework detection — auto-detects i18next, vue-i18n, lingui, react-intl, ngx-translate, svelte-i18n or i18n-js from your package.json
2. Translation file discovery — scans for .json, .yaml, .po, and .pot files in locales/, i18n/, translations/ folders (PO/POT support requires the optional GNU GetText plugin — see Plugin Dependencies)
3. Summary — review and apply the configuration

You can reopen it at any time from Tools > i18n Support Plus > Run Setup Wizard.

Annotations

Highlights i18n keys with visual feedback on resolution status:

Navigation

Ctrl+Click on any i18n key navigates directly to the translation value in the JSON/YAML file.

• Opens the preview locale (the folding language when none is set) rather than asking which file; when that locale lacks the key, every target is offered
• Works with partially resolved keys (navigates to the deepest resolved node)
• Bidirectional: navigate from translation files back to code usage

Code Completion

Autocomplete i18n keys as you type, with full namespace support. Suggestions are drawn from all translation files in the project.

Key Extraction

Extract hardcoded strings into translation files via Alt+Enter intention action. Supports sorted insertion (Extract sorted setting).

Gutter Badges

Line markers in the editor gutter indicate key resolution status at a glance:

Hovering a badge lists the locales; clicking a partial/missing badge triggers the quick fix to create the missing key.

Inlay Hints

Displays the resolved translation value inline after each i18n key expression, directly in the editor. Toggle via Editor > Inlay Hints > i18n translations.

Hover Hints

Ctrl+hover on an i18n key shows a tooltip with all translations grouped by locale, with missing translations shown as "—" and a navigation link (↗) to the translation file.

Preview Locale

i18n: en in the status bar says which locale inlay hints, hover, Ctrl+click and folding read in. Click it to pick another of the project's locales; Switch Preview Locale in the editor's context menu cycles through them, ready for a shortcut. The Preview locale and Preferred folding language settings stay for anyone who wants the two apart.

Code Folding

Replaces i18n keys with their translation values inline for better readability. Toggle with Ctrl+Alt+Shift+T or via the editor context menu.

Rename Refactoring

Rename i18n keys across all translation files and source code references with Shift+F6 — every call site, whether written with its namespace, under a hook namespace or under a key prefix; plural suffixes (_one, _other) are kept.

Bulk Actions

Inspections

Enabled under Settings > Editor > Inspections > i18n Support Plus:

Wildcard Traversal

Intermediate * wildcards in composite key resolution allow matching any segment at a given position. For example, a.*.b matches a.foo.b, a.bar.b, etc. Useful with dynamic keys where the middle segment varies.

Quick Fixes

Tool Window

The I18n tool window (bottom panel) provides a centralized view of all translations in the project.

The toolbar holds the actions — add a translation, add a namespace, refresh, Sync Keys, Scan Orphans, settings —, a search field filtering the tree and the table by key or value (with a result count), and, when several modules are configured, a module selector. A project in which nothing can be read shows where the plugin looked and links to the setup wizard and the settings. The window reloads itself when a translation file changes.

Add translation opens the same dialog as the quick fix: the key is checked as you type, one field per locale says which file it writes to, Copy to empty locales fills the blanks from the reference locale, and the + next to the namespace creates a new one on the spot.

Tree View

Keys grouped by namespace, then by segment. Every key carries its status three times over — an icon, per-locale badges (EN✓ FR✗) and a colour — so it survives a colour-blind reader or a custom theme; a branch shows how many of its keys are fully translated (12/14 (86%)), and a namespace row how complete the namespace is.

• Enter or double-click edits the key, F4 opens the translation file at the key, typing jumps to a key
• Right-click: edit, open file, copy key
• A permanent legend sits at the bottom
• The keys of the default namespace sit in a group named after it — common (default) — when the configuration names a single one

Table View

Flat table: a Namespace column while the rows span several namespaces, the Key, one column per locale, and Usage. Every cell says what it is — a Missing or Empty word with an icon, the value otherwise — before being tinted.

• Locale cells are editable in place; the value is written straight to the file, and the entry created when the locale lacks it
• Namespace filter in the dropdown; right-click the header to hide locale columns
• Scan Orphans (toolbar) fills the Usage column; keys reached only through a dynamic key (t(`status.${kind}`)) are told from unused ones
• Right-click: edit, open file, delete an unused key

Keys Synchronizer

Propagates missing keys across all locales in one click. When a key exists in en.json but not fr.json, the synchronizer creates the missing entry. A batch placeholder dialog lets you fill in values for all missing keys at once.

Stats

Coverage as a matrix: one row per namespace under a Total row, one column per locale. A cell reads 11/13 [===== ] 84.6% — translated keys over the namespace's keys, a bar tinted by tier (≥ 90% complete, ≥ 50% partial, below incomplete), the percentage.

Clicking a cell lists that namespace's untranslated keys in that locale — missing and empty told apart, each next to what it says in the reference locale. Enter or a click opens the translation dialog on the key; F4 opens the reference file.

Multi-Module Support

A monorepo is described as modules in the settings (root directory, path template, key template, framework preset). With two or more, the toolbar's module selector switches the three views from one module to the next; a code file inside a module's root directory resolves its keys against that module's translation files only.

Configuration

Settings > Tools > i18n Support Plus Configuration

Namespaces and separators

Where translations are searched

Modules

One entry per application of a monorepo: a name, a root directory, a path template designating its translation files (locales/{lang}/{ns}.json, messages/{lang}.yml), an optional file template, a key template saying how its code writes keys ({ns}:{key}, {ns}.{key}, {key}) and a framework preset. A diagnostics panel underneath says what each template resolves to.

Key assistance rules

Rules make other calls behave like t: a trigger (translate, i18n.translate, __) turns a function into a translation call, an exclude rule takes one out. Each rule can be limited to a language (js, php) and constrained on the file path, the file's imports or the key — exact, prefix or regular expression, optionally negated.

Folding and preview

Key extraction

Inspections

PHP / gettext

Translation file formats

Per-format settings; the first one is the indentation of the keys generated in YAML files (2 spaces). JSON follows the IDE's code style.

Appearance

Requirements

• IntelliJ IDEA 2025.1+ (build 251–263.*), verified against 2025.1, 2025.2, 2025.3, 2026.1 and 2026.2
• Java 21+

Plugin Dependencies

Installation

From JetBrains Marketplace

Search for "I18n Support Plus" in Settings > Plugins > Marketplace.

From Source

git clone https://github.com/IBRAHIMDANS/i18nSupportPlus.git
cd i18nSupportPlus
./gradlew buildPlugin
# Output: "build/distributions/i18n Support Plus-<version>.zip"

Then install via Settings > Plugins > ⚙️ > Install Plugin from Disk.

Contributing

# Build
./gradlew build

# Run tests
./gradlew test

# Launch IDE with plugin loaded
./gradlew runIde

# Code coverage
./gradlew jacocoTestReport

Requires Java 21 (JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64).

Credits

Originally created by Evgeniy Nyavro.

Maintained by Ibrahim Dansoko. Licensed under MIT.