PDF or Word: Which Should You Send? (With Test Results)
Send a PDF when the document is finished and must look the same for everyone -- a CV, an invoice, a form or a report. Send Word (DOCX) when the other person needs to edit it, or when they ask for Word. Here is why, with what we measured when converting.
The quick answer
PDF is for reading; Word is for editing. If someone has asked for a specific format, use that. Otherwise:
| You are sending... | Send | Why |
|---|---|---|
| A finished CV, letter, invoice or report | Looks the same on every device and is harder to change by accident | |
| A draft someone will edit or comment on | Word (DOCX) | Easy to edit, track changes and comment |
| A form to print or sign | Keeps the exact page layout for printing | |
| A file to a portal that asks for Word | Word (DOCX) | Follow the instructions -- some systems read Word files |
| Something with large photos, by email | In our test it was less than a third of the Word file's size |
Why a PDF looks the same everywhere
A Word file is laid out by whichever program opens it, using the fonts installed on that computer. If a font is missing, the program substitutes another one and lines can re-wrap. A PDF stores the finished pages, and normally the fonts as well.
In our test, the PDF made by our Word to PDF tool had its fonts embedded and its text was still real text: it could be searched and copied. On our server, Calibri is replaced by Carlito, a font with identical letter widths, so the layout is kept. Newer fonts such as Aptos are a known exception, explained in our guide on why a PDF's layout sometimes shifts.
File size: what we measured
We wrote a two-page CV-style document in Word format and converted it with the same code our Word to PDF tool runs. The text-only version went from 36 KB as DOCX to 21 KB as PDF. A version with two 4000 x 3000 photos added went from 6,179 KB to 1,808 KB, because photos are stored in the PDF at 300 pixels for every inch they take up on the page, which is still sharp for printing.
| Test document | Word (DOCX) | PDF from our tool | PDF text searchable? |
|---|---|---|---|
| 2 pages of text | 36 KB | 21 KB | Yes |
| Same text plus two 4000 x 3000 photos (4 pages) | 6,179 KB | 1,808 KB | Yes |
Computer-generated test document; your own files will give different numbers.
Is a PDF safe from editing?
Not completely. A PDF is harder to change by accident, but PDF editors and converters -- including our own PDF to Word converter -- can turn a text-based PDF back into an editable document. If you need to stop casual copying or opening, add a password with our Protect PDF tool; for proof of origin, a visible watermark helps more than a file format.
How to convert
Word to PDF: in Word, choose File > Save As and pick PDF, or upload the .doc or .docx to our Word to PDF converter. PDF to Word: upload the PDF to our PDF to Word converter and you get a .docx. Both are free with no sign-up, and your upload and the converted file are deleted from our server as soon as your download is ready.
Always open the converted file once before you send it, and check the fonts and page breaks.
How we tested
We generated the test document with python-docx (Calibri 11 pt, headings, about two pages of text) and a copy with two computer-generated 4000 x 3000 photos placed 6 inches wide. Both went through the same code our Word to PDF tool runs (LibreOffice 24.2) in a test copy of this site on our own machine; we checked the page count, embedded fonts and searchable text with pypdf. The live server's software versions may differ slightly.