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Best Free PDF Preflight Checker and Editor for Windows, Mac and Linux (2026)

Acrobat Pro, PitStop Pro, free PDF readers and Scribus compared for print work, plus the free app that checks CMYK, overprint and bleed, edits objects and mail merges on Windows, Mac and Linux.

If you design anything that's going to a printer, such as business cards, flyers, menus or packaging, you need to know your PDF is print-ready before it goes. Most PDF apps on Windows, Mac and Linux are built for reading and signing, not for checking CMYK, bleed or overprint. The professional tools that do it are excellent but expensive. Here's how the options compare, and the free app we built at Mangoprint to fill the gap on every platform.

The quick answer

  • For full automated preflight in a busy prepress department: Adobe Acrobat Pro or Enfocus PitStop Pro (paid, Windows and Mac).
  • For reading, signing and annotating: Adobe Acrobat Reader, macOS Preview, Okular or GNOME Papers (free).
  • For building print layouts from scratch: Scribus (free, all platforms).
  • For checking, fixing and editing a finished PDF before it goes to print, for free, on Windows, Mac or Linux: Mangoprint Prepress PDF.

Why print-ready PDFs need more than a PDF viewer

Printers work in CMYK inks, not the RGB colours on your screen. A file that looks perfect in a normal viewer can still come back from the printer wrong, because of problems most viewers simply don't show:

  • RGB images and colours that shift, often duller, when converted to CMYK on press.
  • Spot colours left in the file by accident, which can print as an extra plate or the wrong colour.
  • Overprint settings, including white text set to overprint, which disappears completely on press.
  • Too much total ink in rich blacks and dark areas, causing smudging and slow drying.
  • Missing bleed or wrong trim, leaving white slivers at the edges after cutting.
  • Low resolution images and fonts that aren't embedded.

The professional tools: Acrobat Pro and PitStop Pro

Adobe Acrobat Pro includes Output Preview, colour conversion and a full preflight system, and Enfocus PitStop Pro adds powerful editing and automated fixes on top of Acrobat. Many print companies rely on them every day, and for automated preflight profiles and PDF/X validation they're the industry standard.

They are paid software, though: Acrobat Pro is a subscription, PitStop Pro is a separate licence that runs as a plug-in for Acrobat, and neither is available for Linux. If you're a designer, a small business or a print shop that needs to check and fix files before sending them to print, that's a lot to pay for.

Free PDF readers: Acrobat Reader, Preview, Okular and Papers

Adobe Acrobat Reader (Windows and Mac), macOS Preview, KDE's Okular and GNOME Papers (formerly Evince) on Linux are all great for reading, filling in forms and annotating. They're viewers, though, so they won't show you separations or ink levels, and they can't convert a file to CMYK for print.

Free design apps: Scribus and Inkscape

Scribus is the best free desktop publishing app on any platform, and it understands print: CMYK colour, a preflight verifier and PDF/X export. It's for building layouts, though, and isn't designed to open a finished PDF from another app, check it and fix it. Inkscape is a powerful vector editor, but it's built around RGB colour on screen and its CMYK support is limited.

Mangoprint Prepress PDF: a free prepress checker and editor for Windows, Mac and Linux

We're a print studio, and we kept receiving PDFs with RGB images, missing bleed and white text set to overprint. So we built the tool we wanted: a free, open source app that shows you what your file will really do on press, and fixes the common problems in a few clicks. It runs natively on Windows, Mac and Linux, with exactly the same features on each, so a whole studio can use the same tool whatever computers they're on.

New: edit objects, change colours and mail merge

The latest update turns Mangoprint Prepress PDF from a checker into a proper print editor:

  • Select, move and delete objects: click any object on the page to move it into place or remove it, without going back to the original design file.
  • Edit colours: change the colour of one object, or every object sharing the same fill or stroke across the whole PDF, in one go.
  • Mail merge: merge names and details from a spreadsheet into your PDF, ideal for business cards for a whole team, place cards, certificates and numbered tickets.

What it checks

  • Overprint preview: see what an overprint-aware press will actually produce.
  • Separations and ink readings: hover anywhere to read the percentage of every CMYK and spot plate, plus total ink. Turn plates on and off to inspect knockouts and trapping.
  • White overprint warning: flags anything white that's set to overprint and would vanish on press.
  • RGB and spot colour checks across every page.
  • Image resolution: shows the effective DPI of placed images.
  • Fonts: warns you about fonts that aren't embedded.
  • Trim and bleed: see the page boxes drawn on the page, measured in millimetres.

What it fixes

  • Convert RGB to CMYK, keeping images at full resolution and leaving existing CMYK values alone.
  • Convert spot colours to CMYK.
  • Convert text to outlines.
  • Set trim and bleed boxes and rotate pages.

Your original PDF is never changed. Every edit goes to a working copy, and nothing is saved until you export a new file.

How they compare for print work

Acrobat Pro PitStop Pro Free PDF readers Scribus Mangoprint Prepress PDF
Price Paid subscription Paid licence, plus Acrobat Free Free Free
Windows and Mac Yes Yes Varies Yes Yes
Linux No No Varies Yes Yes
Separations and ink % readings Yes Yes No Not for finished PDFs Yes
Overprint preview Yes Yes No Not for finished PDFs Yes
Convert RGB and spot colours to CMYK Yes Yes No Not for finished PDFs Yes
Move and delete objects in a PDF Yes Yes No Not for finished PDFs Yes
Trim and bleed boxes Yes Yes No Not for finished PDFs Yes
Automated preflight profiles and PDF/X checks Yes Yes No Own layouts Not yet
Open source No No Some Yes Yes

If you run a high-volume prepress department, the paid tools' automation is worth paying for. For everyone else, from designers and small businesses to print shops checking a customer's file, Mangoprint Prepress PDF covers the checks and fixes that matter most for free, on whatever computer you use.

How to download it

Download the latest release from GitHub. Ghostscript, which powers the colour conversions, is built in, so there's nothing else to install.

  • Windows 10 and 11: an installer, or a portable version you can run from a USB stick.
  • Mac: one download for both Apple Silicon and Intel Macs.
  • Linux: an AppImage that runs on Ubuntu, Debian, Fedora, Arch and most other distributions, plus .deb and .rpm packages.

The builds aren't code-signed yet, so Windows and Mac will warn you that the publisher is unverified the first time you open it. The GitHub page explains how to get past that. More details and the roadmap are on the Mangoprint Prepress PDF page.

Adobe Acrobat, Acrobat Reader, Enfocus PitStop Pro, macOS Preview, Okular, GNOME Papers, Evince, Scribus and Inkscape are trademarks or names of their respective owners. Mangoprint isn't affiliated with any of them. Feature comparisons reflect each app's main purpose as of October 2026 and may change; check each product for its latest features and pricing. Mangoprint Prepress PDF is provided free and as is.

Questions

Is there a free alternative to Acrobat Pro for checking print PDFs?

Yes. Mangoprint Prepress PDF is free and shows separations, ink coverage and overprint, converts RGB and spot colours to CMYK, and lets you move, delete and recolour objects. It doesn't do everything Acrobat Pro does, such as automated preflight profiles, but it covers the most common print checks and fixes.

How do I convert a PDF to CMYK for free?

Open it in Mangoprint Prepress PDF, choose Convert RGB to CMYK (and Convert spot colours to CMYK if needed), then export. Images keep their full resolution and existing CMYK colours aren't touched. It works the same on Windows, Mac and Linux.

Can I mail merge names into a PDF for print?

Yes. Mangoprint Prepress PDF can merge names and details from a spreadsheet into your PDF, so you can print business cards for a whole team, place cards or certificates from one design.

Is there Adobe Acrobat for Linux?

No. Adobe doesn't make a current version of Acrobat for Linux, so Mangoprint Prepress PDF is one of the few ways to check and fix print PDFs on Linux.

Is Mangoprint Prepress PDF really free?

Yes. It's free and open source under the AGPL-3.0 licence, with no account or subscription.

Need something printed?

We're a print studio in Maidstone, Kent. Every order gets a free artwork check, and you can collect from us in ME15 or have it delivered anywhere in the UK.

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