Free CMYK / colour space checker
Check RGB vs CMYK in your PDF before print
RGB files look fine on screen and surprise you on press. This free check measures colour spaces against a CMYK production profile and returns a clear Prepta Score with every finding.
- RGB, mixed spaces and profile mismatches (expected CMYK / grayscale)
- Plain-language findings you can send to a designer
- Same run also checks bleed, fonts, resolution and PDF/X markers
- Free diagnostic — Prepta can convert colour automatically when you need a production file
Checking a file for someone else?
No account. One file at a time.
Runs the full free public preflight — not a single-rule toy.
Your file is deleted when the report is ready.
Free artwork check
IDLERelated tools and reading
Prefer the full overview? Use the free PDF preflight checker. Or read RGB vs CMYK for printing first, then come back and check a file.
- Print file checker
Check a JPG, PNG, TIFF, HEIC, PSD, AI, EPS, SVG or PDF for print — free.
- PDF bleed checker
Upload a PDF. Check bleed and trim against a real production profile — free.
- PDF resolution checker
Check placed image DPI in a PDF against a print profile — free.
- PDF/X checker
Check PDF/X-4 markers in a PDF — free marker check for print workflows.
- PDF font checker
Check whether fonts are embedded for print — free Prepta Score.
- PDF transparency checker
Check live transparency in a PDF for print — free.
Common questions
How do I check if a PDF is CMYK?
Upload it here. The free checker reports colour mode against a CMYK print profile — including RGB images, DeviceRGB content and mixed colour spaces.
Why does RGB matter for print?
Screens use RGB; most print processes use CMYK (or spot). Unconverted RGB can shift colour, soft blacks and brand colours. Catching it before plate or press saves reprints.
Will this convert my PDF to CMYK?
No. The free check is diagnostic only. Full Prepta can convert within your production profile and re-validate the result.
Is this a full colour-management suite?
It is a practical preflight colour check for print readiness, not a substitute for soft-proofing every ink limit. Use it to catch the wrong space early, then soft-proof critical jobs in your RIP or proofing workflow.