Why 1 MB is still a common cap
Plenty of systems still set a 1 MB attachment limit: court and tribunal e-filing, insurance claims, tenders, and a number of recruitment portals. Phone scanning apps, on the other hand, happily produce 10 MB PDFs. This preset bridges that gap.
What happens to your file
pdf.js renders each page inside your browser, and pdf-lib stitches the pages back together as JPEG images. With a 1 MB budget we can usually keep high resolution, so scanned text, stamps and signatures stay crisp. The tool starts at 150 DPI and steps down only if needed; if the first try lands well under 1 MB, it steps up (up to 300 DPI) and keeps the sharpest version that still fits, so you use the space you are allowed.
Honest limits
- Text turns into pictures, so search, copy and screen readers no longer see it. Keep the original for your records.
- Born-digital PDFs that are already small can grow; we warn you if the result is not smaller.
- Huge scans (100+ pages) may not fit 1 MB at a readable quality. Split them with Split PDF and upload in parts.
Need something smaller?
Use the 500 KB preset for application portals, or the 200 KB preset for single certificates.
Where the 1 MB limit applies
Court and tribunal e-filing, insurance claim uploads, tender portals, learning management systems and some recruitment forms. It is also a courteous size for email attachments.
Expected results at 1 MB
| Pages (scanned) | Budget per page | What to expect |
|---|---|---|
| 1 page | about 1024 KB | Scans stay sharp; photos and stamps clear |
| 3 pages | about 341 KB | Scans stay sharp; photos and stamps clear |
| 10 pages | about 102 KB | Text crisp on screen; photos fine |
| 25 pages | about 41 KB | Readable on screen; small print may soften |
Born-digital PDFs (exported from Word or a bank website) are often already under the limit – check the size first. These are rough guides: colour, page size and scan noise change the result.
Can’t get below 1 MB?
When the tool reports the closest size above the target, the document simply has more page detail than the budget allows. In order of effect:
- Send fewer pages. Remove blank, duplicate or unneeded pages with Delete PDF pages, or keep only the required ones with Extract PDF pages.
- Split it. If the portal allows several uploads, cut the file into parts with Split PDF and compress each part.
- Rescan in greyscale at 150 DPI. Colour and 300–600 DPI scans waste most of the budget on paper texture.
- Crop dark borders from phone scans before making the PDF – black edges cost a lot of bytes.