Find the broken bits.
Keep the translation yours.
Compare your source with a language file. Find missing keys, changed types and broken placeholders before they reach your interface.
1. Add your files
One source + one target; 1 MiB each. Nested JSON objects/arrays or flat key,value CSV.
2. Choose checks
Key/type checks and unsupported-syntax warnings always run. Digit differences can be valid changes in number style, dates or grammar. Text expansion does not prove screen fit.
3. Review & export
Reports may contain private text. They are not safe to post publicly by default. CSV text that could be a spreadsheet formula is prefixed with an apostrophe; JSON retains the original text.
What this check can—and cannot—tell you
Supported here
- JSON objects and arrays; paths use JSON Pointer escaping, so a slash in a key stays distinct.
- Flat CSV with exactly
key,valueheaders, quoted commas/newlines and UTF-8 text. - Simple
{name},{0},{{name}}and common printf tokens such as%s,%d,%1$s,%.2f. - Duplicate keys rejected. Input files stay unchanged.
Still needs your review
- Not a translator, grammar checker or release certification.
- ICU plural/select, custom placeholders, dynamic printf widths/precision and app-specific syntax need their own validator.
- No XLIFF, PO, XML, YAML or CSV schema beyond key,value.
- JSON nesting limited to 50 levels and 50,000 values per file. Do not use production secrets.
Check a release, not just one language.
The offline Batch Edition adds up to 20 target files, 5 MiB per file, reusable rules and a ZIP with separate language reports. Single-language checks stay free.
One-time offline download. Check the supported formats before buying.
Offline batch edition — $7 USDKeep the free starter
Download the free offline starter ZIP
Extract the ZIP and open index.html. One source and one target, 1 MiB each; missing/extra keys, types, empty text, supported placeholders and optional number/length advisories; CSV/JSON reports.