What “readability” actually means
“Readable” depends on what you’re sending. For typed text it means letters stay sharp at normal zoom and when printed. For a scanned form it means the stamp, signature and tiny print stay clear, and the boxes don’t shift.
The point isn’t the absolute smallest file: it’s the smallest file that still does its job without you having to squint.
Where PDF size really comes from
Open a typical 8 MB PDF and you will usually find: most images, some fonts and vector graphics, and the rest is structure and metadata. Text itself is tiny.
That is why two documents with the same number of pages can differ many times in size: one is pure text, the other is scanned photos of text. Knowing which type you have tells you how much you can save.
- Typed PDFs: light to begin with: trimming hidden font data helps nicely.
- Scanned PDFs: really photos inside a PDF: images are the main weight.
- Mixed PDFs: typed pages stay light; pages with photos are the heavy ones.
Choose the right target before you compress
Check the limit before you start. A portal might say 200 KB, email is usually looser. If you pick the wrong target you’ll just do the work twice.
If there’s no stated limit, start with Medium in Custom, look at the new size, and only go stronger if you actually need to.
Step-by-step: compress without losing clarity
You usually don’t need to edit the PDF first: but a quick 30-second check can save a lot of hassle.
- 1. Check the source: if you scanned it, was it at 300 DPI colour? Re-scan at 150–200 DPI grayscale if colour is not required: this alone can halve the size.
- 2. Remove blank pages or duplicate scans: they add weight for nothing.
- 3. In Shrinklyy, pick a target (e.g., 500 KB for email, 200 KB for strict portals) or use Custom → Medium.
- 4. After download, zoom to 150% and check the smallest text, seals, and signatures. If anything looks soft, undo and try a gentler setting.
- 5. Keep the original file untouched. Save the compressed copy with a clear name like ‘resume-200kb.pdf’.
Common mistakes that hurt readability
The most common mistake is taking a file you already compressed and running it through again. Each pass makes photos a bit softer and saves less. Always go back to the original.
Another is forcing 100 KB on a photo-heavy file. A six-page colour scan will look rough at 100 KB and clean at 500 KB. Match the target to what’s inside, not to the smallest number.
- Avoid screenshotting a PDF and re-making it: you add a generation of loss for no benefit.
- Don’t lower scan DPI below 150 for documents with small print; the text itself becomes the problem.
- If a portal rejects your PDF, check that it is not encrypted or corrupted before trying stronger compression.
Frequently asked questions
Quick answers to the questions readers ask most about this topic.
Only if you push the target too low for the content. Text stays sharp at Medium and even High for most documents; photos show quality loss first. Preview at 150% zoom: if small print is crisp, you are fine.
Scanned pages are images. A colour scan at 300 DPI has far more pixels than the text needs. Rescan in grayscale at 150–200 DPI, or allow 300–500 KB if colour and stamps must stay.
Yes | Shrinklyy renders each page and re-encodes images with balanced JPEG quality in your browser. No server adds watermarks or re-compresses behind the scenes.
Try these tools
Matched to the workflow described in this guide.