Conversions fail quietly. Check these four things.

1. Page count

Compare the number of pages before and after. A page that vanished usually means content was dropped rather than re-flowed, and it is the fastest signal that something went wrong.

2. Tables and numbers

Tables are where conversions do their quietest damage: a column boundary shifts and values land one cell over. Check the totals, not just the appearance — a table can look right and add up wrong.

3. Anything not in the main text flow

Footnotes, headers, footers, captions, sidebars, and page numbers are anchored differently from body text and are the usual casualties. Look at one page that has each.

4. Fonts and characters

Accented characters, currency symbols, and mathematical notation are where an encoding problem surfaces first. If a document has any, read one line containing them rather than trusting a glance.

Where two versions need comparing properly — a contract before and after, say — comparing them side by side is more reliable than reading both and hoping you notice.

Where the damage usually is

Conversions are most fragile wherever a human made a visual decision that the file format never recorded as structure. A column break created by pressing return, a table drawn with tab stops, a heading that is just larger bold text — none of those carry any meaning a converter can preserve.

That is why the first and last pages tend to survive and the middle does not. Skim the pages that look most designed, and read the ones that look most like a spreadsheet.

Check it where it will be opened

A converted document that looks right in the tool that produced it can re-flow in a different word processor, on a different operating system, or on a phone. If you know where it is going, open it there once.

Send a PDF instead when the layout matters more than editing. A document converted for editing and then shared as-is is the most common way a broken table reaches a customer.

When the file has to survive for years

For archiving or submission to an authority, converting to PDF/A embeds the fonts and removes the dependencies that make a file render differently in ten years. Some submission systems require it outright.

Do that conversion last, after the content is settled. PDF/A is a preservation format, not a working one, and re-editing usually means going back to the source anyway.

What to check first when the clock is running

If you only have a minute, check three things in this order: the numbers in tables, the last page, and anything that was in a header or footer. Those are where conversions fail most often and where a mistake travels furthest.

Tables lose column boundaries before they lose words, so a figure can land under the wrong heading while every character on the page is correct. The last page is where truncation shows up. Headers, footers and page numbers are frequently reflowed into the body, which is harmless in a draft and embarrassing in something you send to a client.