Why subtitle and promo text punch above their weight

The subtitle appears directly under your app name on the product page and in many browse contexts. It is indexed for search alongside the title and keyword field, so it is both a conversion line and an ASO slot. Promotional text sits above the description and can be updated without submitting a new binary — which makes it the best place for seasonal offers, feature launches, and market-specific hooks.

If either field stays in English while the rest of the locale is localized, the page feels unfinished. Shoppers notice. Treat subtitle and promo as first-class localization work, not an afterthought after screenshots.

Pair subtitle and promo localization with screenshot captions and the rest of your metadata. Tools like App Store Localizer (https://asolocalization.com) help you keep metadata and screenshots in the same pass so no locale ships half-English.

Know the hard limits: 30 and 170 characters

Apple enforces strict caps. The subtitle is 30 characters. Promotional text is 170 characters. Those counts include spaces and punctuation. There is no soft overflow — App Store Connect rejects anything longer, and truncated copy looks broken even when it somehow slips through a draft.

  • Subtitle: ≤30 characters — one clear benefit or category cue.
  • Promotional text: ≤170 characters — a short pitch you can refresh anytime.
  • Title is also 30 characters; do not waste subtitle repeating the same words.
  • Count after localization. German compounds and Japanese scripts expand differently than English.

Always measure the localized string, not the English source. A 28-character English subtitle can become 40+ characters after a literal translation.

Rewrite per market — do not translate literally

Literal translation is the fastest way to blow the limit and sound unnatural. Subtitles and promo lines need to be rewritten for each locale: same intent, different words, native rhythm. In some markets a category noun works better; in others a verb-led benefit lands harder.

  1. Start from the benefit you want that market to feel in one glance.
  2. Draft 2–3 native options without looking at the English word order.
  3. Trim to the character cap by cutting filler, not by chopping mid-word.
  4. Have a native speaker (or a strong bilingual reviewer) pick the winner for tone.

Promotional text is especially sensitive to culture: discount framing, urgency, and feature naming differ by storefront. A launch line that works in en-US may feel pushy or vague in JP or DE — rewrite the hook, keep the truth.

Keyword strategy: subtitle vs title vs keyword field

Apple indexes title, subtitle, and the 100-character keyword field. Repeating the same terms across all three wastes indexing room and makes the page read robotic. Use each slot for a different job.

  • Title: brand plus the strongest primary keyword if it fits in 30 characters.
  • Subtitle: a complementary pitch — secondary keywords or a clear benefit the title did not cover.
  • Keyword field: remaining search variants, synonyms, and misspellings — comma-separated, no spaces after commas when you need every character.
  • Promo text: conversion copy first. It is visible, but treat ranking keywords as a bonus, not the reason it exists.

If your title already says “Photo Editor,” your subtitle should not say “Photo Editing App.” Use the 30 characters for something new: speed, AI, offline, templates — whatever differentiates you in that market.

Common mistakes that kill conversions

  • Copy-pasting English into every locale “temporarily” and never coming back.
  • Truncating mid-phrase to hit 30/170 instead of rewriting shorter.
  • Stuffing the subtitle with keywords until it stops sounding like a human product.
  • Leaving promotional text blank or identical across markets for months.
  • Updating screenshots and description while forgetting subtitle and promo on the same locale page.
  • Using a machine translation without a character-budget pass.

Any one of these makes a localized listing feel cheaper than a competitor who rewrote five short lines carefully. The fix is process, not more tools — though a metadata workflow that surfaces limits per locale helps.

A practical workflow checklist

Use this when you add a new locale or refresh an existing one:

  1. List target locales and open each editable language in App Store Connect.
  2. For every locale, draft a subtitle ≤30 characters that does not repeat the title’s keywords.
  3. Draft promotional text ≤170 characters with a market-specific hook (feature, season, or offer).
  4. Count characters in the localized string; rewrite until both fields fit cleanly.
  5. Align subtitle tone with screenshot captions so the page tells one story.
  6. Paste subtitle and promo in the same pass as description and keywords — never leave them for “later.”
  7. Spot-check the live or preview product page per storefront after publish.

When you localize screenshots and metadata together at https://asolocalization.com, keep a short checklist for subtitle and promo on every locale so those two fields never lag behind the images.

Ship the rewrite, then iterate. Promotional text is free to change without a new binary — use that flexibility for A/B-style refreshes across your top markets while the subtitle stays stable as your secondary ranking line.