Translation memory for App Store metadata — why it matters at scale

Translation memory is a staple of generic TMS tools (Lokalise, Crowdin), but it's structurally different for App Store metadata. Here's why apps re-translating the same description across 39 locales every release are quietly burning money.

Translation memory (TM) — the practice of storing approved past translations and reusing them for unchanged source text — is the single most-cited cost-saver in commercial translation. Generic TMS tools (Lokalise, Crowdin, Phrase) have shipped TM for two decades. For App Store metadata, it's been almost entirely absent.

Why the App Store metadata case is different

App Store fields are short (30 chars for name, 80 for subtitle, 4000 for description, 100 for keywords) but updated frequently. Most apps tweak their description every 2–3 releases. Without translation memory, every release re-translates every locale's full description — usually 80–90% of which is unchanged from the prior version. That's 80–90% wasted LLM tokens or human translator hours.

Add char-limit enforcement per locale (Russian and German routinely expand 30–40% over English) and the problem compounds: every re-translation also re-runs the fitting work that already produced an acceptable result last release.

What TM looks like for App Store metadata

Three components: (1) per-app store of approved translations keyed by source-text hash + locale; (2) on re-translate, the engine first matches each unchanged source string to its stored translation; (3) only the diff (new or edited source text) is sent to the LLM. Result: a re-translation that's normally 600 tokens × 39 languages × 5 fields turns into 60 tokens × the same matrix.

The compound effect

Apps that ship monthly updates and re-translate every locale save roughly 80% of their per-release localization cost once TM is in place. For agencies managing 10+ client apps, the savings hit thousands of dollars annually in API spend or translator hours.

What this means for app builders

If you re-localize metadata on every release and aren't using translation memory, you're paying for the same work 5–10 times a year. Tools that specifically handle App Store TM are rare (AppsOps and doloc are the two we're aware of). Generic TMS won't do it because the App Store field structure is bespoke.