Why does translated text never fit the original layout?

Most people want the same thing: translate this PDF and keep it looking exactly as it does now. That's a fair thing to want, but it is close to impossible, and the quality of the translation has nothing to do with it.

Translated text changes size

Translating the same sentence out of English often changes its length by a lot:

• German: often 30% longer, sometimes more. Compound nouns are single long words that can't be broken.
• French and Spanish: 15–25% longer.
• Bangla and Hindi: similar length in characters, but the script is taller, with marks above and below the line, so lines get crowded at the same line height.
• Chinese and Japanese: usually much shorter in characters, and often wider per character.
• Arabic and Hebrew: run right to left, so alignment, indents and anything tied to an edge all flip.

A button that fits "Save" does not fit "Speichern". A table column sized for "Date" does not fit "Fecha de vencimiento".

Why a PDF makes it worse than a web page

A web page reflows. A box grows, the text below moves down, and the layout absorbs the change.

A PDF does not reflow. Every letter sits at a fixed position. There is no box to grow, so a longer line runs over whatever is to its right, or off the page. To keep the original layout, one of these has to happen:

1. Shrinking the translated text until it fits, which produces a document with a dozen different type sizes.
2. Truncating it, which loses meaning.
3. Re-laying-out the page, which is no longer the same design.

Any "translate PDF, keep formatting" service has to pick one of those three. Usually it is the first, and it often isn't mentioned.

What works better

Take the text out, translate it, and place it where you want it.

Translate PDF returns the translation paragraph by paragraph with the original beside it, so you can read and check it. From there:

• If you only needed to understand the document, you are done. Most of the time, that is all people need.
• If you need a translated document, put the text where you want it with the PDF editor, where you can resize and move it to suit the language.
• If you have the original as a Word or InDesign file, translate that and export it again. Its layout can adjust to the new text.

The check nobody does

Whichever way you go, look at the longest item on the page: the widest table cell, the longest heading, the tightest button. Those overflow first, so they tell you whether the layout held up.