Compress PDF to 20 KB
Shrink PDF file size while keeping the best quality possible.
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How to compress a PDF to 20 KB
20 KB is about as small as PDF limits get. It suits a single simple page: a signature or thumb-impression scan, or a short typed declaration. This page is set to 20 KB and keeps the most readable version that fits, or tells you how close it got.
Add a one-page PDF, cropped to the signature or document.
Check the size box shows 20 KB.
Click Compress PDF, then read the note under the file to see whether it fits.
What a 20 KB PDF can hold
20 KB is roughly the size of a small thumbnail image, so a PDF this small can carry one simple page and nothing more. Exam and recruitment forms use limits like this for a scanned signature, a thumb impression or a short handwritten declaration, where the content is a few dark strokes on white paper. A typed one-page letter with no images is normally under 20 KB already and is returned unchanged.
A scanned certificate with a coloured border, a seal and fine print is a different matter. The compressor lowers image quality and then shrinks the page image until it has tried its smallest setting. If the file is still over 20,000 bytes, you get that smallest version with a note of its real size. Treat the note as the answer to whether this document can meet a 20 KB limit at all.
Preparing a signature or thumb impression page
Almost all of the saving at this size comes from what you scan, not from compression:
- Sign, or press your thumb, on clean white paper and scan only that area, not the whole A4 sheet.
- Choose black and white, or greyscale if the ink is faint; colour adds data that a signature does not need.
- If the form states a range, such as 10 to 20 KB, and your file lands below it, Increase PDF Size pads it up without touching the page.
Compress PDF to 20 KB FAQ
Only a simple one: dark ink on white paper, such as a signature, a thumb impression or a few lines of text. A colour certificate with a seal and small print will not stay readable at this size.
Then compress to the form's upper limit instead. If the file ends up below 20 KB, Increase PDF Size pads it up without changing what the pages show.
No. The tool runs entirely in your browser, so your files are processed on your own device and never leave it.
Yes. Every PDFCraftly tool is free, with no sign-up, no watermark and no email required.
Guides
- USCIS File Too Large? Compress a PDF Under 12 MB for Evidence UploadsUSCIS online accounts reject evidence files over 12 MB and password-protected PDFs. How to shrink a scan under the limit without uploading it anywhere.
- CEAC Document Upload: Get NVC Scans Under the 4 MB File Size LimitThe State Department's CEAC portal takes immigrant visa scans up to 4 MB each, in color, as PDF or JPG. How to compress an I-864 or civil document to fit.
- Compress a PDF for a UK Visa Application: UKVCAS, VFS Global and TLScontact Upload LimitsUKVCAS takes PDF, JPG and PNG files up to 7.25 MB each; VFS and TLScontact show their limit on the upload page. How to shrink visa documents to fit.
- Compress a PDF for a UK University Application: 2 MB, 4 MB and 5 MB Portal LimitsLSE and Edinburgh cap each upload at 2 MB, Oxford at 4 MB and UCL at 5 MB. How to compress transcripts, certificates and references to fit each portal.
- IRCC File Size Limit: How to Compress a PDF Under 4 MB for Your UploadIRCC accepts 4 MB per file in most online accounts and 5 MB in the IRCC Portal, one file per field. How to compress and combine PDFs to fit.
- ImmiAccount Attach Documents: How to Compress a PDF Under 5 MBImmiAccount accepts documents up to 5 MB each and up to 60 per person, and rejects encrypted PDFs. How to compress, merge and unlock files to fit.
More optimize tools
- Compress JPGNewShrink photos and signatures to a size you choose, like 50 KB.
- Increase PDF SizeNewMake a PDF bigger in KB to meet a portal's minimum file size.
- Increase JPG SizeNewMake a photo or signature bigger in KB to meet a form's minimum size.
- Repair PDFNewTry to rebuild a damaged or corrupted PDF and save a clean copy.
- OCR PDFTurn scanned PDFs into searchable, selectable text.
- Remove AnnotationsStrip comments, highlights and markups from a PDF.