Will the text still be sharp?

Yes for typed PDFs, since text is not an image. For scans, text is part of the image; at a medium setting it stays clearly readable.

Can I compress a password-protected PDF?

Unlock it first with Unlock PDF (you need the password), compress it, and protect it again if needed.

What if the portal wants under 500 KB?

Use the strongest compression and, if needed, split the document so each part fits. For a single image, Compress to exact KB can target a precise size.

Guide

How to compress a PDF under 1 MB

A 1 MB limit is common on government portals, job applications and university forms, and a phone-scanned document often comes in at five or ten times that. Almost all of that weight is images. Compress PDF re-encodes the images inside the file at a lower resolution and quality, which is where the savings are, and keeps the text sharp.

Steps

1Open Compress PDF and drop the file.
2Pick a compression level. Start in the middle; move to the strongest setting if the file is still over 1 MB.
3Check the new size shown before you download.
4If it is still too big, split the PDF into parts, or lower the scan resolution and try again.
5Download the compressed PDF and upload it to the portal.

Open Compress PDF

Why is my PDF so big?

Text in a PDF is tiny. A 10-page typed document is usually under 200 KB. Scanned pages, on the other hand, are full-page photos, often 2 to 5 MB each at phone-camera resolution. A PDF made of scans is a photo album, and shrinking it means shrinking the photos.

How far can you go?

A scanned page at 150 DPI in greyscale is readable and about 100 to 200 KB. That means a five-page scan fits under 1 MB comfortably; a twenty-page scan may not without going to a lower quality. For typed documents that are already small, compression will barely change the size because there are no images to shrink.

Scan smaller in the first place

Scan at 150 DPI for documents, not 300 or 600.
Use greyscale or black-and-white for text pages; colour only where it matters.
Crop to the page. Scan to PDF does this automatically from phone photos.

Privacy

The PDFs that need to fit under 1 MB are often ID documents, transcripts and certificates. Every tool runs in your browser, so your files never leave your computer.

Questions

Will the text still be sharp?: Yes for typed PDFs, since text is not an image. For scans, text is part of the image; at a medium setting it stays clearly readable.
Can I compress a password-protected PDF?: Unlock it first with Unlock PDF (you need the password), compress it, and protect it again if needed.
What if the portal wants under 500 KB?: Use the strongest compression and, if needed, split the document so each part fits. For a single image, Compress to exact KB can target a precise size.