Catch localization file problems before they reach the design.

What does the localization file preflight checker do?

Inspect one XLIFF file or compare source and target JSON or CSV files for missing keys, empty translations, placeholder drift, duplicate copy, and structural errors. The immediate result is a localization structure and placeholder QA report. That makes the tool useful when a focused question needs an answer before a file is handed off, a campaign is trafficked, or a production workflow begins.

The scope is intentionally narrow. It is designed for checking one set of strings, localization files, or copy constraints, not for replacing the complete production process. A useful result should make the next decision clearer while leaving the original file, design, or workflow under the user’s control.

Your files and inputs are processed locally in this browser and are not uploaded to Hypermatic. Local processing reduces unnecessary data exposure, but it does not remove the need to follow the privacy, confidentiality, and retention requirements that apply to the source material.

How should the localization file preflight checker be used?

Start with the same input that will be used in production whenever possible. Draft content, substitute files, and approximate dimensions can be useful during exploration, but the final check should use the actual export, final copy, destination, or supported range.

Work through the steps in order and keep the generated result beside the source. If the result identifies a warning, decide whether it is a real production problem, an acceptable tradeoff, or a limitation of a browser-based inspection before changing the underlying work.

• Choose a source JSON, CSV, XLF, or XLIFF file and add a target file when required.
• Compare keys, target values, placeholders, duplicates, and untranslated strings locally.
• Correct structural problems before importing, syncing, reviewing, or laying out localized designs.

How should the result be interpreted?

A browser tool can make measurable signals visible, but it cannot reproduce every application, platform, rendering engine, policy, or team constraint. Treat the report as evidence for a decision rather than a universal guarantee. The strongest verification is the source content system, linguistic review, runtime placeholders, and the final Figma layouts.

Pay particular attention to edge cases that are easy to miss during a quick check: unusual fonts, long or localized content, hidden metadata, external dependencies, different aspect ratios, browser-specific behavior, and last-minute source changes. Re-run the tool whenever the production input changes materially.

• Treat identical source and target values as a review queue, not automatic proof of a missing translation.
• Never remove placeholders merely to make a translation pass validation.
• Run visual expansion and RTL checks after structural QA.

Common questions about localization file preflight checker

Which localization formats are supported? The checker reads nested JSON, simple key/value CSV, and XLF or XLIFF translation units. More specialized plural and vendor extensions may require a dedicated localization system.

What is placeholder drift? Placeholder drift occurs when a variable or formatting token in the source is missing, renamed, duplicated, or changed in the target, potentially breaking the final interface.

Is the localization file preflight checker free? Yes. You can use it without an account or signup. The focused result is generated directly in your browser.

When does CopyDoc become the better workflow?

The free tool is the right choice for a quick individual check, calculation, preview, or template. It remains useful even if the task only occurs once and no broader production workflow is needed.

CopyDoc becomes more practical when the same job turns into syncing, localizing, importing, and updating content across complete Figma designs. At that point, keeping the work close to the Figma source reduces repeated exports, copy-and-paste steps, inconsistent decisions, and handoff drift.

Before adopting any workflow, compare the time spent on the recurring manual process with the setup and review required by the tool. The goal is not to add another application; it is to remove repetitive work while preserving the quality checks that still need human judgment.