You finished the cover letter, you proofread it, you're ready to send. Then the export dialog asks: PDF or Word? It feels like a coin flip. It isn't.

The right format depends on three things: who's reading, how they're processing the application, and whether the job ad gives you any instruction. The first one wins by default.

Default: send a PDF

For 90% of applications, PDF is the safer pick. Three concrete reasons:

• Layout stays put. Fonts, margins, line breaks, the spacing between the date and the salutation — all locked. Word docs render differently on different machines, especially across Windows / Mac / mobile Word versions.
• It looks finished. A PDF reads as a final document. A .docx reads as a draft someone can edit. The signal matters even if the recruiter never thinks about it consciously.
• No accidental edits. A Word file can be marked up, scribbled in, or saved over by a passing recruiter. A PDF stays exactly as you sent it.

Name the file firstname-lastname-cover-letter.pdf — no version numbers, no "final-v3" tags. Recruiters routinely receive 200+ files; a clean filename is the first thing they see.

When Word makes more sense

Three situations where .docx beats PDF:

1. The job ad says so. Some application portals only accept .docx. Some recruiting agencies edit your letter into their template before forwarding. If the instructions ask for Word, send Word.
2. You're applying through a staffing or recruiting agency. Agencies often rebrand candidate materials for their end clients. A Word file makes that process painless.
3. The role is at a Microsoft-aligned organization where editing in Word is the cultural norm. Rare, but happens — usually in legal, government, and certain corporate procurement teams.

For everything else — direct applications, startups, mid-market companies, most agency portals — default to PDF.

What about ATS parsing?

This is where it gets interesting. Most modern ATS systems (Greenhouse, Lever, Ashby, Workable) parse both PDF and Word equally well. Older systems sometimes do better with Word — but those systems are also the ones least likely to read cover letters in the first place.

If you're worried about ATS specifically for cover letters, the bigger risks are:

• Tables. Avoid them entirely in cover letters. Plain paragraphs only.
• Headers and footers. Many ATS strip them. Keep your contact info in the body.
• Images, logos, decorative fonts. All risky. Plain text on a plain template parses cleanly.

If the same letter parses correctly in both formats, the format itself doesn't move the needle. The structure of the document does.

Saving a clean PDF

A PDF is only as good as the export. Three things that go wrong:

• Compressed file size mangles the text. Choose "high quality" or "print quality" when exporting from Word or Google Docs. A 200 KB cover letter is fine. A 30 KB one usually means font compression.
• Embedded fonts get lost. If you used a non-standard font (Inter, Open Sans, anything not bundled with Word), check "Embed fonts" in the PDF export options. Otherwise the recruiter sees a fallback font and your spacing drifts.
• Page breaks in the wrong place. Print preview before exporting. A cover letter that breaks one bullet onto a second page looks careless.

Filename conventions that recruiters notice

The filename is the first impression. Bad versions:

• cover-letter.pdf — anonymous.
• final-cover-letter-v2-real-FINAL.docx — looks unhinged.
• john_smith_CL.pdf — too cryptic.

Good version: john-smith-cover-letter-acme.pdf. Hyphens, lowercase, includes the company name. The company name is optional but useful — it signals you wrote this letter for them, not a generic broadcast.

One file or both?

Don't send both. It's not extra effort, it's extra confusion. The recruiter wonders which one is the real one. Pick the format the role calls for and commit.

If the application portal has a single attachment slot, the choice is made for you anyway.

Quick decision tree

• Application portal accepts both: PDF.
• Job ad says "send a Word document": Word.
• Applying through a staffing agency: Word.
• Cold email to a hiring manager: PDF.
• Unsure: PDF.

If you keep a single cover letter source in a tool like Postulit (or even Google Docs), export to whichever format the situation calls for. Same content, two outputs, zero version drift.

The file format is the smallest decision in your application. Get it right by default, and spend the saved energy on the part that actually persuades — the first sentence of the letter itself.