PDF Preflight
PDFCheck a PDF before it goes to print — fonts, image resolution, colour, bleed, transparency and more — in your browser, never uploaded.
PDF Preflight checks a PDF before it goes to the printer, the way a print shop would, without uploading it. It reads the file's own structure and reports fonts that are not embedded, images whose resolution at the size they are placed is too low, RGB and spot colours, missing trim boxes and bleed, transparency, overprint, hairlines, form fields and more — each with the page it is on and a Locate button that outlines it. Choose digital print, offset print or screen, change the thresholds to match your printer, and download the report. Colours are identified, not converted, and nothing is claimed that reading the file cannot show. Some problems it can also fix safely, into a new file — removing comments and scripts, flattening form fields, setting trim and bleed boxes — and it checks the fixed copy again straight away; colours, image resolution and fine lines are left to the artwork. Choose where it will be printed — a built-in ECI condition or your printer's own ICC profile — and a print preview shows each page on that paper, with the colours it cannot reach marked and the ink each area takes; the ink limit comes from the profile itself. When RGB is the problem, it can convert the pictures and colours to CMYK for that condition, black text to black ink only, and embed the profile as the output intent — into a new file, checked again at once.
Why use PDF Preflight
100% private
Your PDF files are processed locally and never uploaded.
Instant
No upload or download wait — it runs at the speed of your device.
Free to start
Use it free every day; go Pro for unlimited runs.
No install
Works in any modern browser. No sign-up to begin.
How to use PDF Preflight
- 1Drop the PDF
It is read in your browser; nothing is uploaded.
- 2Choose where it is going
Digital print, offset print or screen — and change the resolution, bleed or line-width limits to your printer's.
- 3Fix what it finds
Problems come first, each with its page and a Locate button that outlines it on the page. Download the report for the printer or your records.
Frequently asked questions
Is my PDF uploaded for the check?
No. The file is read in your browser and nothing about it is sent to Alvseike — not the file, its name or anything in it.
How is image resolution worked out?
As effective resolution: the image's pixels over the size it is actually placed at on the page, following every scaling inside the PDF. A 3000-pixel photo shown across a whole A3 page is not a 300 PPI image, and the check says so.
Does it convert colours or measure ink coverage?
It measures what it can measure exactly. The ink of CMYK colours the file sets for text, lines and shapes is summed from the file's own values and checked against the press limit. The print preview converts the page with a real ICC profile — three ECI profiles are built in, or load your own, such as the ones NADA publishes for Norwegian newspapers and magazines — and shows how it will look, what falls outside the paper's colours, and the ink the conversion lays down. The file itself is never changed.
Can it fix what it finds?
Some of it. Comments and markup, form fields, JavaScript and missing trim and bleed boxes can be fixed safely, because the fix changes exactly what the check found. You choose which, the fixes are saved as a new file, and that file is checked again so you can see what changed. Colours, image resolution and hairlines are never changed automatically — those are decisions about the artwork.
Can it convert RGB to CMYK?
Yes, once you choose where it will be printed. Pictures and colours are converted with that condition's ICC profile by LittleCMS, the colour engine professional tools use; neutral greys and black text become black ink only, so type prints sharp; and the profile is embedded as the output intent. RGB gradients and inline images are left as they are and listed, rather than guessed at. The result is a new file, checked again straight away — the original is never changed.
Does it certify PDF/X?
No. It checks the things a printer checks first, but a PDF/X claim needs a full standards validator. The report says what was read, not that a standard is met.