The advice you will find splits evenly between "always PDF" and "always Word", which is a reliable sign that the question is wrong. The format matters far less than how the file was made.
A PDF exported from Word and a PDF exported from a design tool are the same file type and behave completely differently. One parses perfectly; the other may contain no text at all.
The short answer
Send a PDF exported from a word processor, unless the employer asks for something else, in which case send what they asked for, because that is what their system is set up to read.
The reason to prefer PDF is not parsing. It is that a PDF renders identically for everyone. A .docx reflows depending on the reader's fonts, Word version and page setup, so your carefully spaced two-page resume can arrive as three pages with a heading stranded at the bottom.
Where the old advice came from
"Never send a PDF" was genuinely correct once. Systems built in the 2000s handled Word far better, and PDF text extraction was unreliable. Taleo in particular had a poor reputation for it.
That was fifteen or more years ago. Extraction improved, the tooling standardised, and modern systems handle PDFs routinely. The advice persisted because it is repeated in career articles that copy each other, and because nobody has an incentive to retract it.
The kernel of truth that survives is narrower and more important: PDFs can contain no text, whereas a .docx always does. That is the real risk, and it is entirely avoidable.
The distinction that actually matters
| How the PDF was made | Parses? |
|---|---|
| Exported from Word, Google Docs or Pages | Yes, real text throughout |
| Exported from LaTeX | Yes, though ligatures occasionally extract oddly |
| Exported from Canva, Figma or Illustrator | Usually, unless the text was outlined or rasterised |
| Printed, then scanned | No. It is a photograph |
| Photographed on a phone and converted | No. Also a photograph |
| Exported with "flatten" or "outline text" on | No. Letters became shapes |
The ten-second test
Open your PDF and try to select a sentence with your mouse.
Words highlight individually? There is a text layer. A parser can read it.
A rectangle covers the whole block, or nothing selects? It is an image, and your application arrives blank however good it looks. Export a fresh copy from a word processor.
This single test catches the only genuinely fatal file problem, and it costs nothing. The ATS checker makes the same check and tells you explicitly, along with which pages are affected in a mixed document.
When .docx is the better choice
When the employer asks for it. They know their own system. Follow the instruction.
When a recruitment agency asks for it. Agencies routinely restyle resumes onto their own letterhead before sending them to clients, and an editable file saves them retyping, which means yours gets sent sooner.
When the upload form only accepts it. Rare now, but it happens with older portals.
In each case, check how your .docx reflows: open it on another machine if you can, and avoid text boxes, which are the .docx equivalent of the two-column problem, they float outside the main text flow and frequently extract in the wrong order or not at all.
Formats to avoid entirely
.pages, .odt, often unreadable by the employer's tooling.
.txt, parses perfectly and looks like you did not try.
.jpg or .png, no text at all.
A link to Google Docs, many systems cannot follow it, permissions frequently break, and you can see who opened it, which some recruiters dislike.
File naming
Minor, but free: Priya-Sharma-Resume.pdf rather than resume-final-v3-USE-THIS.pdf. Some systems display the filename to the recruiter, and yours sits in a folder alongside a hundred files called "resume.pdf".
Whatever format you settle on, the structural rules still apply, see the formatting guide, and the two-column problem in particular, since it affects PDF and .docx alike.