Video Localization Checklist: Item-by-Item, From Script to Publishing

Localization does not end with "getting the subtitles translated". When a video that works well for a domestic audience is moved overseas as-is, the failures are often not in the translation itself but in details like pacing, units of measurement and date formats. This checklist is organized in four layers; we recommend going through it in two passes: part one when the script is finalized, parts two through four after the finished video is exported.

1. Content Layer

[ ] Voiceover pacing: pacing that feels natural for Chinese is often too fast in the target language — leave room for pauses
[ ] Cultural references and internet slang: literal translation usually fails; swap in a local equivalent or cut them
[ ] Proper nouns: brand names, product names and personal names translated consistently across the whole video; prepare a glossary in advance
[ ] Units of measurement: metric or imperial — weight, length, temperature and dimensions all need converting
[ ] Date formats: avoid writing 03/04/2026 — US style is month/day/year, continental European style is day/month/year, and the same digits point to two different dates
[ ] Numbers and currency: thousands separators and decimal points are written the opposite way (1,000.50 and 1.000,50 are the same number); confirm currency symbol placement too
[ ] Humor and the butt of jokes: self-deprecation and jokes can turn into offense in a different cultural context
[ ] Platforms mentioned: do the apps, websites and payment methods shown in the video actually work in the target market

2. Subtitle Layer

[ ] Translation quality: machine translation as the base, with proper nouns and terminology reviewed by a human
[ ] Line breaking: break at semantic units, do not copy the source punctuation
[ ] Length and speed: Chinese 12–15 characters per caption at 4–6 characters per second; English 32–38 characters per caption at 12–17 characters per second
[ ] Caption duration: no shorter than 1 second, no longer than 6 seconds
[ ] Bilingual order: original on top or translation on top — once decided, keep it consistent across the whole video
[ ] Safe zones: avoid UI-covered areas; on vertical video watch the bottom and right side especially
[ ] Font size: set by the longer line; for two-line subtitles keep the whole block within the height limit
[ ] Contrast: add an outline, shadow or semi-transparent backing bar on bright backgrounds
[ ] Timeline sync: check cue by cue, do not align only the beginning
[ ] Punctuation and encoding: do not mix Chinese and English punctuation; save files as UTF-8 to avoid garbled text

When you only have the original-language subtitle file, start with the bilingual SRT generator to get an "original + translation" file; to attach multiple language tracks, use the SRT translator to produce each language version separately.

3. Technical Layer

[ ] Aspect ratio: vertical 9:16, horizontal 16:9, square 1:1 — pick by target platform
[ ] Resolution: mainstream platforms all accept 1080p and above; do not force low-resolution footage
[ ] Duration: long-form and short-form platforms have different duration caps; exceeding them means truncation
[ ] Bitrate and file size: too low looks blurry, too high uploads slowly, and the platform will compress it again anyway
[ ] Audio loudness: consistent across the whole video; viewers swipe away from levels that jump around
[ ] Font licensing: commercial fonts require licenses, and cross-region distribution makes the license scope even more important to confirm

4. Publishing Layer

[ ] Title localization: rewrite it around the target language's search habits, do not translate it word for word
[ ] Description and tags: switch to keywords and hashtags commonly used in the target market
[ ] Cover text: the words on the cover need translating too — few words, large font size
[ ] Cover safe zone: platforms overlay badges on cover corners, so keep key information away from them
[ ] Publishing time: post during active hours in the target time zone, not according to your own schedule
[ ] Spec re-check: go through each platform's cover size, ratio and format requirements once more
[ ] Post-publish maintenance: comment interaction after publishing affects later distribution — assign someone to watch it
[ ] Subtitle reuse: upload the same subtitle file to the platform as a CC track while you are at it

FAQ

Are English-only subtitles enough?

If your target market is English-speaking, yes. But English itself splits into markets with different wording and spelling conventions. SmileSub supports mutual translation across 20 languages including Chinese, English, Japanese and Korean — when one video needs to cover several markets, adding more tracks costs very little.

Machine translation or human translation?

Machine translation as the base with human review is currently the best value combination. Machines produce the first draft and the bilingual alignment; humans focus on proper nouns, industry terminology and tone. Fully human translation does not scale to batch publishing.

Do vertical and horizontal videos need separate subtitle setups?

The subtitle file can be reused, but the layout parameters need adjusting separately. The safe zones and font size ratios of vertical video differ completely from horizontal — applying them directly leads to covered or undersized subtitles, so check them separately on export.

How long does one pass of this checklist take?

Once familiar, about ten-odd minutes for a video of a few minutes. What really costs time is rework after problems are found — the earlier you run the checklist, the easier it gets.