Placeholder validation

Localization Placeholder Checker

Placeholder validation protects runtime values such as names, counts, prices, dates, and links from being changed during localization.

Examples

Source JSON
{
  "cart.items": "{count} items in your cart",
  "cart.total": "Total: {amount}"
}
Target JSON
{
  "cart.items": "カートに{total}件の商品があります",
  "cart.total": "合計: amount"
}
Expected finding
cart.items: {count} missing, {total} extra
cart.total: {amount} missing
Release impact
The UI may display the wrong number, fail interpolation, or show a literal word instead of a runtime value.

Who owns placeholder safety

Developers define placeholder syntax. Translators and vendors preserve it while adapting the surrounding sentence. Localization PMs and QA teams need a clear report showing that the delivered file still contains the runtime tokens the product expects.

Placeholder issues tend to appear after translation memory reuse, manual editing, or copy changes where the visible sentence changes but a required token is accidentally changed or removed.

Why valid JSON is not enough

A string with the wrong placeholder is still valid JSON. The parser does not know that {count} is required or that {total} belongs to another string.

LocaleQA extracts supported token patterns from matching source and target paths and compares token names and counts consistently. It does not judge grammar around the token.

Manual versus automated detection

Reviewers can visually spot obvious token changes, but braces, percent markers, ICU-like fragments, and repeated tokens are hard to catch by eye in dense files. Automated placeholder validation catches every matching string path consistently.

Related pages