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Translation Length Planner for Social Captions

Paste an English caption, pick the languages you will translate it into, and see how long each version is likely to be against the limits on X, Instagram, Threads, Bluesky, Mastodon and TikTok. You also get a character budget for the English so every translation fits.

131 characters (131 counted the X way)

Target languages

Longest English caption that fits every language

Using the high end of each estimate. Keep your English at or under these numbers and every selected translation should fit.

X
200
Limit: Japanese
Instagram
1629
Limit: German
Threads
370
Limit: German
Bluesky
222
Limit: German
Mastodon
370
Limit: German
TikTok
1629
Limit: German

English (source)

  • X131 of 280FitsWrite at most 280 English characters for this one
  • Instagram131 of 2200FitsWrite at most 2200 English characters for this one
  • Threads131 of 500FitsWrite at most 500 English characters for this one
  • Bluesky131 of 300FitsWrite at most 300 English characters for this one
  • Mastodon131 of 500FitsWrite at most 500 English characters for this one
  • TikTok131 of 2200FitsWrite at most 2200 English characters for this one

German

Short caption, so the published short-text table applies: 115 to 140% of the English length

  • X151 to 183 of 280FitsWrite at most 207 English characters for this one
  • Instagram151 to 183 of 2200FitsWrite at most 1629 English characters for this one
  • Threads151 to 183 of 500FitsWrite at most 370 English characters for this one
  • Bluesky151 to 183 of 300FitsWrite at most 222 English characters for this one
  • Mastodon151 to 183 of 500FitsWrite at most 370 English characters for this one
  • TikTok151 to 183 of 2200FitsWrite at most 1629 English characters for this one

French

Short caption, so the published short-text table applies: 120 to 126% of the English length

  • X157 to 166 of 280FitsWrite at most 233 English characters for this one
  • Instagram157 to 166 of 2200FitsWrite at most 1833 English characters for this one
  • Threads157 to 166 of 500FitsWrite at most 417 English characters for this one
  • Bluesky157 to 166 of 300FitsWrite at most 250 English characters for this one
  • Mastodon157 to 166 of 500FitsWrite at most 417 English characters for this one
  • TikTok157 to 166 of 2200FitsWrite at most 1833 English characters for this one

Spanish

Short caption, so the published short-text table applies: 120 to 135% of the English length

  • X157 to 177 of 280FitsWrite at most 215 English characters for this one
  • Instagram157 to 177 of 2200FitsWrite at most 1692 English characters for this one
  • Threads157 to 177 of 500FitsWrite at most 384 English characters for this one
  • Bluesky157 to 177 of 300FitsWrite at most 231 English characters for this one
  • Mastodon157 to 177 of 500FitsWrite at most 384 English characters for this one
  • TikTok157 to 177 of 2200FitsWrite at most 1692 English characters for this one

Japanese

Planning range: 50 to 70% of the English length

  • X131 to 183 of 280FitsWrite at most 200 English characters for this one
  • Instagram66 to 92 of 2200FitsWrite at most 3143 English characters for this one
  • Threads66 to 92 of 500FitsWrite at most 715 English characters for this one
  • Bluesky66 to 92 of 300FitsWrite at most 429 English characters for this one
  • Mastodon66 to 92 of 500FitsWrite at most 715 English characters for this one
  • TikTok66 to 92 of 2200FitsWrite at most 3143 English characters for this one

These are estimates from planning ranges, not a translation and not a measurement. Hashtags, links and mentions are counted as ordinary characters, and X shortens links in its own way. A translator or a translation tool will give the real length.

How to use the Translation Length Planner for Social Captions

  1. Paste the English caption. The page counts its length the way each network does, including the X rule that emoji and some scripts count double.
  2. Tick your target languages. Choose from German, French, Spanish, Finnish, Arabic, Japanese and Chinese, or add another language with your own percentage change.
  3. Read the status for each network. Each language shows an estimated range against the limit and a label: fits, might overflow or overflows.
  4. Check the safe English length. The top panel shows the longest English caption that should fit every language you ticked on each network.
  5. Trim the English first. Shorten the source to the budget before you send it to a translator, so you are not cutting a translation afterwards.

How the length estimates are made

What it checks

The estimated translated length is the English length multiplied by a low and a high factor for the language. On X the base is the weighted length, where characters up to U+10FF and a few punctuation ranges weigh one and everything else weighs two, and every Japanese or Chinese character weighs two. The budget is the longest English caption whose high estimate fits the network limit, and the safe length is the smallest budget among the languages you ticked.

Where the figures come from

For European languages and English captions of 70 characters or fewer, the tool uses the average expansion by source length that IBM published and the W3C article Text size in translation quotes: 200 to 300 percent up to 10 characters, 180 to 200 up to 20, 160 to 180 up to 30, 140 to 160 up to 50 and 151 to 170 up to 70 (as printed), and about 130 percent above that. To avoid a sudden jump at 70 characters, the estimate eases from the last row down to the language range over the next 70 characters. We read the W3C page in October 2026. It does not give a figure per language, so the ranges for longer captions are working assumptions: German +10 to 35 percent, French +15 to 20, Spanish +15 to 30, Finnish +30 to 40, Arabic +20 to 25, Japanese and Chinese 50 to 70 percent of the English length.

The X weighting comes from the X developer documentation on counting characters. Other limits come from the Instagram and TikTok developer documentation, the Bluesky post lexicon and the Mastodon source.

Limitations

A tone of voice, a slang term or a hashtag can change a translated length by more than any average. Links, mentions and hashtags are counted as plain characters, X shortens links on its own terms, and the tool does not translate anything. Use it to set a sensible budget for the English, then check the finished translation in a character counter.

Frequently asked questions

Why does a translated caption usually get longer?

Many languages need more words or longer words to say the same thing as English. German and Finnish also join several words into one long word. The W3C article on text size in translation describes this, and quotes IBM figures showing that short English text grows the most.

Do Japanese and Chinese captions get shorter?

In characters, usually yes, because each character carries more meaning, so we plan for roughly half to 70 percent of the English length. But X counts Chinese, Japanese and Korean characters as two each, so on X the saving shrinks or disappears. The tool applies that rule.

How accurate are the percentages?

They are planning ranges, not measurements, and a real translation can land outside them. The W3C article confirms the direction of the change and prints the IBM table by source length, which the tool uses for captions up to 70 characters in European languages, easing into the language ranges after that. The per-language ranges for longer captions are our own working assumptions, which is why the page states them and lets you add your own.

Which limits does it check?

X 280 weighted characters, Instagram 2,200, Threads 500, Bluesky 300 graphemes, Mastodon 500 (the software default, which an instance may change) and TikTok 2,200. They come from each network documentation and source code, checked in October 2026.

What does might overflow mean?

The low end of the range fits but the high end does not. The translation could go either way, so the safe move is to trim the English until the high end fits too.

Is my caption stored or sent anywhere?

No. The counting and the maths run in your browser and nothing is uploaded.