PDF/X is an ISO standard for print-ready PDF files. It requires embedded fonts, an ICC color profile, and a defined OutputIntent — so the printer can reproduce colors accurately. PDF/X-1a is the most common for CMYK print; X-3 allows RGB; X-4 supports transparency and layers.

Which PDF/X version should I choose?

Quick decision tree: X-1a for offset print (no transparency, CMYK only — the safe default, 90% of printers want this). X-3 is X-1a but allows RGB, rarely used in practice. X-4 is the modern format for digital presses and preserves live transparency and layers. In doubt? Pick X-1a — and always ask your printer first if you can.

What is an ICC profile?

An ICC profile defines how colors in your PDF should be interpreted in print. For European and Danish offset print, Coated FOGRA39 is the standard. We embed it automatically, but you can also choose ISO Coated v2, US Web Coated SWOP or GRACoL depending on your printer's preference.

What happens to transparency in X-1a?

PDF/X-1a does not allow transparency. We automatically flatten transparent elements (rasterising or computing overlap) so the output is compatible. If you have complex transparency effects, choose X-4 instead.

Do all fonts need to be embedded?

Yes — PDF/X requires all fonts to be embedded. We embed what we can automatically. If your PDF is missing fonts we do not have, use the Embed Fonts tool first or Outline Fonts as a fallback.

Yes — converting to PDF/X-1a, X-3 and X-4 is free at PDF.dk. No watermark, no signup for basic use.

Convert PDF to PDF/X (X-1a, X-3, X-4)

Convert your PDF to the PDF/X standard. Embeds fonts, ICC profile (FOGRA39) and OutputIntent. Free online tool — required by most professional printers.

Frequently Asked Questions

What is PDF/X?: PDF/X is an ISO standard for print-ready PDF files. It requires embedded fonts, an ICC color profile, and a defined OutputIntent — so the printer can reproduce colors accurately. PDF/X-1a is the most common for CMYK print; X-3 allows RGB; X-4 supports transparency and layers.
Which PDF/X version should I choose?: Quick decision tree: X-1a for offset print (no transparency, CMYK only — the safe default, 90% of printers want this). X-3 is X-1a but allows RGB, rarely used in practice. X-4 is the modern format for digital presses and preserves live transparency and layers. In doubt? Pick X-1a — and always ask your printer first if you can.
What is an ICC profile?: An ICC profile defines how colors in your PDF should be interpreted in print. For European and Danish offset print, Coated FOGRA39 is the standard. We embed it automatically, but you can also choose ISO Coated v2, US Web Coated SWOP or GRACoL depending on your printer's preference.
What happens to transparency in X-1a?: PDF/X-1a does not allow transparency. We automatically flatten transparent elements (rasterising or computing overlap) so the output is compatible. If you have complex transparency effects, choose X-4 instead.
Do all fonts need to be embedded?: Yes — PDF/X requires all fonts to be embedded. We embed what we can automatically. If your PDF is missing fonts we do not have, use the Embed Fonts tool first or Outline Fonts as a fallback.
Is the tool free?: Yes — converting to PDF/X-1a, X-3 and X-4 is free at PDF.dk. No watermark, no signup for basic use.

How to

Upload your PDF file
Choose the PDF/X version (X-1a is the standard for most printers)
Pick an ICC profile (FOGRA39 is the European standard)
Click "Convert to PDF/X" and download the result