AstrologerAI: an AI astrology app localized into 52 languages
How the AstrologerAI app translated its entire experience into 52 languages with LocalePack — 6.3M tokens for $58.73 — to reach a worldwide audience in their own language.
Purpose-built for Opera extensions
AI localization for Opera extensions
Upload your source messages.json, pick target languages, pay once, and download a ready-to-ship _locales ZIP.
Placeholder-safe translations
Opera messages.json compliant
Transparent pricing
How it works
Three simple steps to localize your Opera extension. Translations run after payment—we queue jobs and generate the ZIP in minutes.
01
Upload
Drop your source messages.json file. We parse it instantly and validate the Opera extension format.
02
Select languages & see price
Choose from 52 languages. See transparent pricing based on your file size before you pay.
03
Download ZIP
Pay once via Stripe. We generate all _locales/{lang}/messages.json files and bundle them into a ZIP.
Live pricing demo
Transparent pricing estimator
See exactly what you'll pay before uploading. Final quote is computed after upload based on string length and languages selected.
1. Upload file
Drop messages.json here
or click to browse
Opera extension format only. Max 500KB.
2. Select languages
|
3 of 55 languages selected
3. Your estimate
Languages selected3
Final price calculated after file upload on checkout page
One-time payment • No subscription
Built for developers
Purpose-built for Opera extension locale format. Not a generic translation tool.
Opera format aware
Built specifically for Opera extension messages.json structure with message, description, and placeholders support.
Placeholder protection
Preserves $PLACEHOLDER$ syntax exactly as-is. Your variables stay intact across all languages.
Description context
We read your description fields and use them as context hints for more accurate AI translations.
ZIP export ready
Download a ZIP with correct _locales/{lang}/messages.json folder structure. Drop it into your extension.
Parallel processing
All languages are translated simultaneously. Most jobs complete in under 5 minutes.
One-time payment
No subscriptions, no monthly fees. Pay once per job, download forever.
How Opera extension i18n works
Opera extensions are built on the Chromium WebExtension platform — the same _locales/{locale}/messages.json structure as Chrome. The chrome.i18n API is available in Opera without modification, and LocalePack's ZIP output is drop-in compatible.
_locales/ folder structure
_locales/
├── en/
│ └── messages.json ← default_locale
├── de/
│ └── messages.json
├── fr/
│ └── messages.json
└── ja/
└── messages.jsonmessages.json
{
"appName": {
"message": "My Extension",
"description": "Extension name"
},
"greeting": {
"message": "Hello, $USER$!",
"placeholders": {
"user": { "content": "$1" }
}
}
}Runtime API
chrome.i18nExample call
chrome.i18n.getMessage("appName")Required in manifest
"default_locale"Opera is built on Chromium. Any _locales ZIP that works for Chrome will work for Opera as-is.
The Opera Addons store serves users across many locales. A complete _locales/ folder significantly improves discoverability for non-English speaking users.
Opera runs the Chromium extension stack
Opera extensions are built on the same Chromium WebExtension platform, so the localization work transfers directly.
- Drop-in Chrome compatibility
- Opera uses the same _locales/{locale}/messages.json structure. The chrome.i18n API is available without modification and LocalePack's ZIP is drop-in compatible.
- Chromium locale resolution
- Opera resolves locales the Chromium way, so underscore-separated folder names and the supported-code list behave identically to Chrome.
- Reuse one localization pass
- If you already ship a localized Chrome extension, the same _locales/ folder covers Opera — there is no second translation pass to run.
- A smaller store, less competition
- Opera Add-ons serves a large non-English user base, and comparatively few extensions there ship complete _locales/ folders.
The same silent-ignore behaviour applies: a locale folder Chromium does not recognise is skipped without any warning.
Why not just use generic tools?
General-purpose translation tools don't understand Opera extension format.
LocalePack | Manual translation | Generic TMS | |
|---|---|---|---|
| Setup time | 2 minutes | Hours per language | 30+ minutes |
| Cost transparency | |||
| Opera format safety | |||
| Placeholder protection | |||
| Speed (52 languages) | < 5 min | Weeks | Hours |
| Best for | Opera extensions | Small projects | Enterprise web apps |
Success Cases
Real projects that used LocalePack to reach a global audience in up to 52 languages.
DevToys.pro: 400% international traffic growth across 52 languages
How the DevToys.pro web app translated its entire UI into 52 languages with LocalePack — 5.8M tokens for $58.44 — and quadrupled its international organic traffic.
DevToys New Tab: a Chrome extension localized UI + store listing in 52 languages
How the DevToys New Tab Chrome extension localized both its in-extension UI and its Chrome Web Store listing into 52 languages to reach a global audience.
LocalePack localized itself into 52 languages — with LocalePack
We used our own tool to translate the entire LocalePack site into 52 languages — 2.9M tokens for $27.37 — so developers worldwide find us in their own language.
Trusted by extension developers
“Saved me hours of tedious work. Uploaded my messages.json, got back perfect translations in the exact format I needed.”
Sarah K.
Indie dev, AdBlock extension
“Finally a tool that understands Opera extension format. No more fixing broken placeholders after translation.”
Marcus T.
Extension maintainer
“Transparent pricing was the selling point. I knew exactly what I'd pay before uploading anything.”
Dev J.
Open source contributor
52
Locales supported
100%
Placeholder-safe output
ZIP
Ready to ship
Frequently asked questions
Everything you need to know about LocalePack.
Related developer guides
Deep dives on the formats, APIs and errors behind this page — written for developers, not translators.
Chrome extension i18n: _locales structure and default_locale
How to set up the _locales folder, what default_locale does in manifest.json, and how Chrome picks the right messages.json at runtime.
messages.json format explained (with placeholders)
A complete reference for the WebExtension messages.json format: the message, description, and placeholders fields, $PLACEHOLDER$ syntax, $1 positional substitutions, and common mistakes.
Chrome extension locale codes: all 55
Every locale code Chrome accepts as a _locales folder name, with language and native names, the underscore-vs-hyphen trap that makes pt-BR silently ignored, and how Chrome picks a locale at runtime.
default_locale: rules and common errors
Why default_locale is required when _locales exists, what happens when you omit it, and how to fix the most common manifest validation errors.