PDF Preflight: check your file before printing

Drop a PDF and get a preliminary technical check report in seconds: bleed and trim line, colour spaces and separations, effective image resolution, font embedding, ink coverage, overprint, transparency and PDF/X metadata.

The selected PDF is analysed locally in your browser. The tool does not send the file or its content to our server.

This is an automated preliminary check of a PDF file: trim size and bleed, colours and ink coverage, fonts, image resolution, overprint, transparency, PDF/X metadata. It does not replace your printer’s preflight and does not assess content, page order or conformity with your order; anything not checked is listed in the report under limitations. No issues found does not mean the file is print-ready or PDF/X compliant. Confirm the requirements and the file with your chosen printer; the decision to order printing is yours. The rules for using the Tools are set out in the Terms of Service.

Defaults: CMYK + spots, 300 dpi, 3 mm bleed and 3 mm safe zone (adjustable in the fields below), RGB as an error, transparency as a warning.
Drag a PDF here or click to choose
PDF 1.x and 2.0 (incl. PDF/X, PDF/A) · up to 300 MB · multi-page

What is PDF preflight and why do printers require it?

Preflight is the inspection of a production file before it goes to press. It checks what the screen doesn't show: whether pages carry bleed and a correctly defined trim line (TrimBox), whether colours are CMYK rather than RGB, whether photos keep enough effective resolution after scaling, whether every font is embedded, whether total ink coverage (TAC) stays within the press limit, whether white objects are set to overprint, and whether the file contains transparency, layers, form fields or security. Any of these can stop a job, or worse, slip through and come off the press as a white sliver along the edge, shifted colours or garbled characters.

What exactly does this tool check?

The engine reads the PDF structure itself (xref, object streams; damaged files are reconstructed) and interprets each page's content stream: it tracks transformation matrices, colour spaces (DeviceCMYK, ICCBased, Separation, DeviceN, Lab, Indexed), images and their effective DPI where placed, line weights, type sizes, overprint and transparency state. On top come the metadata: PDF version, PDF/X declaration and OutputIntent with the ICC profile description, layers, form fields, attachments, JavaScript, encryption. Page thumbnails are rendered by pdf.js, but every finding comes from our own analysis, which is why it also works on files whose preview fails.

Limits worth knowing

Image ink coverage is computed from pixels for CMYK data without lossy compression (Flate, RAW, LZW); for CMYK JPEGs we only note that they were not sampled. Encrypted files are analysed structurally only. Printers require unprotected files anyway. Preflight does not replace a colour proof: it judges technical correctness, not aesthetics.

File has issues? Contact us: we will fix and print it (you send the file after we get in touch)