twineconvert

free · in-browser · no upload

PO to JSON
Converter

Drop your .po file. We'll convert it to JSON right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .po, .pot

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a .po from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your JSON the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert PO → JSON

What this conversion is actually for

Modern frontend i18n stacks (react-i18next, vue-i18n, next-intl, formatjs) consume JSON, not PO. po-to-json bridges the gap: structured array of entries with msgctxt, msgid, msgid_plural, msgstr (string or array), comments, references, and flags all preserved. Drop the JSON straight into your locales folder or feed it through your translation pipeline.

A real example

You inherited a legacy gettext-based backend but the new React frontend uses react-i18next. Drop your existing `messages.po` here, get a JSON array, and write a 10-line script that flattens it into the `{ "key": "translation" }` shape react-i18next wants (or use it as-is in libraries that consume PO-style JSON).

Troubleshooting

I want a flat key:value JSON, not an array.

Our output is the lossless representation (array of entry objects) so plurals and contexts survive. Most frontend libs (react-i18next, vue-i18n) actually want flat key:value. After conversion, run `JSON.parse(out).reduce((acc, e) => (acc[e.msgid] = Array.isArray(e.msgstr) ? e.msgstr[0] : e.msgstr, acc), {})` to flatten — but you'll lose plural variants. Trade-off you have to make consciously.

Formats involved

About .po and JSON

.po, Gettext Portable Object

A PO file is the interchange format used by every gettext-based software localization toolchain: GNU gettext, Babel (Python), Poedit, Lokalise, Crowdin, Weblate, Transifex, polib, react-i18next, Django, Symfony, WordPress translations, and many more. Each entry pairs a source string (`msgid`) with its translation (`msgstr`), plus optional disambiguation context (`msgctxt`), plural forms (`msgid_plural` / `msgstr[N]`), translator/developer comments, source-file references, and gettext flags. Spec dates to 1995 with the original GNU gettext release; still the de-facto standard 30 years later.

How to open

Poedit (free, all platforms) is the most common editor. Lokalise/Crowdin/Weblate/Transifex import PO directly via web upload. Any text editor opens them as plain text. Linguists prefer Poedit for translation memory and validation; developers usually edit them in their IDE.

Full .po format guide →
JSON, JavaScript Object Notation

JSON is a lightweight text format for structured data, nested objects, arrays, strings, numbers, booleans. It's the lingua franca of web APIs, configuration files, and data interchange between programs. Human-readable when formatted, machine-parseable in every programming language, and roughly half the size of equivalent XML.

How to open

Any text editor reads JSON. Browsers display .json files in a formatted tree view. VS Code and similar editors highlight syntax.

Full JSON format guide →

Related tools

Convert other files to JSON

Convert your .po to other formats

FAQ

Common questions

Is this PO → JSON converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert .po to JSON?

Software localization (UI strings, error messages, in-app text in every language). API responses, configuration files, structured data interchange. The most common reason to convert is compatibility, JSON works in places where .po doesn't, or vice versa.

How do I open a .po file in the first place?

Poedit (free, all platforms) is the most common editor. Lokalise/Crowdin/Weblate/Transifex import PO directly via web upload. Any text editor opens them as plain text. Linguists prefer Poedit for translation memory and validation; developers usually edit them in their IDE.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.