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Chrome JSON Messages

Everything you need to know about Chrome JSON Messages

File Extensions         .json
API extension json
Format Options No
Import   Yes
Export   Yes
Pluralization supported?       No
Descriptions supported?   Yes

Google provides internationalization support for Chrome extensions. Localized strings for Chrome extensions are stored in a JSON file often named messages.json. Chrome JSON files have a slightly different structure than JSON files used for localization on other platforms. For Chrome JSON, strings that need translation are placed in the sub-key “message” nested under each unit key-value pair. You may also add a “description” to each key-value pair.

Code Sample

  "boolean_key": {
    "message": "--- true\n"
  "empty_string_translation": {
    "message": ""
  "key_with_description": {
    "message": "Check it! Key has a description! (In some formats)",
    "description": "I'm a very important description for this key!"
  "key_with_line-break": {
    "message": "This translations contains\na line-break."
  "nested.deeply.key": {
    "message": "  I'm nested deeply."
  "nested.key": {
    "message": "This key is nested inside a namespace."
  "null_translation": {
    "message": null
  "pluralized_key.one": {
    "message": "Only one pluralization found."
  "pluralized_key.other": {
    "message": "Wow, you have %s pluralizations!"
  "pluralized_key.zero": {
    "message": "You have no pluralization."
  "sample_collection": {
    "message": "---\n- first item\n- second item\n- third item\n"
  "simple_key": {
    "message": "I am a simple key with a simple message."
  "unverified_key": {
    "message": "Not yet verified waiting for it. (In some formats we also export this status)"

More information