Runs in your browser · nothing is uploaded

Compress PDF

Compress PDF files without uploading them. Lossless clean-up keeps text as text; the Strong mode turns pages into images for scans and photo-heavy files. You always see the real sizes — and the original if nothing was saved.

Compression

Remove metadata — title, author, XMP, embedded page thumbnails and editor private data (e.g. Illustrator's)

Also shrink JPEG photos — lossy for those photos only; text and drawings are untouched

If a result isn't smaller than your file, you'll be told and offered the original instead.

How each mode works

Lossless clean-up (keeps text selectable)

The PDF is parsed with pdf-lib in a background worker.
Objects nothing refers to — left behind by earlier edits — are dropped.
Uncompressed streams are Flate-compressed, and Flate streams are re-compressed at the highest level. Both are lossless.
Optionally: title/author, XMP metadata, embedded page thumbnails and editor private data are removed.
Optionally: plain RGB JPEG photos are re-encoded at your quality and maximum size — kept only if at least 5% smaller.
The file is saved with compressed object streams, re-opened to check it has the same number of pages, and compared with your original.

Strong (pages become images — text no longer selectable or searchable)

Each page is drawn with PDF.js at the DPI you choose (one page at a time, to limit memory), saved as a JPEG, and placed on a page of exactly the original size in a new PDF. Very large pages are capped at 25 megapixels.

Worked example

A scanned 20-page A4 document at 100 dpi becomes twenty 827 × 1,169 pixel JPEGs. If the new file is smaller you get it with the percentage saved; if it isn't (common for text-only PDFs), you're told “No saving” and offered the original.

Strong mode: pixels per page

PDF page sizes are measured in points (1/72 inch), so pixels = points × DPI ÷ 72. Calculated when this page was built, by the same code the tool runs.

DPI	A4 page (pixels)	US Letter page (pixels)
72	595 × 842 (0.5 MP)	612 × 792 (0.5 MP)
100	827 × 1,169 (1 MP)	850 × 1,100 (0.9 MP)
150	1,240 × 1,754 (2.2 MP)	1,275 × 1,650 (2.1 MP)

A4 is 210 × 297 mm (ISO 216); US Letter is 8.5 × 11 in; a PDF point is 1/72 inch (ISO 32000). Checked 2026-10-07.

Limitations, plainly

Savings vary a lot. Text-only PDFs from modern apps often shrink by little or nothing in Lossless mode. Big gains come from scans and photos.
Photo shrinking only touches plain RGB JPEGs. CMYK, grayscale, masked, PNG-style (Flate) and JPEG 2000 images are left as they are.
Forms and annotations: Lossless mode keeps form fields, links and comments. Strong mode flattens their current appearance into the picture — fields can no longer be filled and links don't work.
Encrypted PDFs can't be processed — remove the password with Unlock PDF first. Digital signatures are invalidated by any change.
Large files (up to 200 MB each, 20 at a time) are processed in memory; Strong mode on hundreds of pages can take a while. You can stop at any time.

Frequently asked questions

How do I reduce the size of a PDF?+

Add the PDF, pick a mode and press Compress. Start with Lossless clean-up — it keeps text selectable. If the file is mostly scans or photos and still too big, turn on “Also shrink JPEG photos”, or use Strong mode, which turns each page into a JPEG.

Why didn't my PDF get smaller?+

Many PDFs are already compact — for example ones exported by modern word processors. Re-saving can't remove what the file needs. When the result isn't smaller, the tool says so, shows the real sizes and offers your original instead of a bigger file.

Will compressing a PDF make the text blurry?+

Not in Lossless clean-up: text, vector drawings and fonts are not changed. Photo shrinking only re-encodes JPEG photos. Strong mode does turn text into pixels — at 72 dpi small print can blur, at 150 dpi it usually stays readable.

What is the difference between the two modes?+

Lossless clean-up rebuilds the file more compactly (object streams, maximum Flate compression, unused objects and optionally metadata removed); the content is the same. Strong mode renders every page as an image and builds a new PDF from those images: often much smaller for scans, but text is no longer selectable or searchable and links and form fields are lost.

Which DPI should I use in Strong mode?+

72 dpi is smallest and fine for reading on screen. 100 dpi is a sensible middle ground. 150 dpi keeps small print readable when printed. An A4 page at 150 dpi is 1,240 × 1,754 pixels.

Can I compress a password-protected PDF?+

No. Encrypted PDFs can't be opened here — remove the password first with Unlock PDF (tools.northlane.live/unlock-pdf/), then compress the unlocked copy. A digitally signed PDF can be compressed, but the signature will no longer be valid.

Is my PDF uploaded?+

No. Lossless clean-up runs in a background worker in your browser, and Strong mode draws pages with PDF.js on your device. The file never leaves your computer or phone.

Can I compress several PDFs at once?+

Yes. Add up to 20 PDFs (200 MB each) and they're all compressed with the same settings. Download each file on its own, or all of them in one ZIP once two or more are done.

How do I make a PDF small enough to email?+

Many email services cap attachments at roughly 20–25 MB, and some company systems allow less. Try Lossless clean-up first, then turn on “Also shrink JPEG photos”; if a scanned file is still too big, Strong mode at 100 dpi usually shrinks it the most. The before and after sizes show exactly where you are.

What do photo quality and largest photo side do?+

They apply when “Also shrink JPEG photos” is on. Quality (75 by default) sets how hard each photo is re-compressed, and Largest photo side (1,600 px by default; 2,400 px, 1,200 px or Keep the size) scales big photos down. A re-encoded photo is only kept if it's at least 5% smaller, and only plain RGB JPEGs are touched.

What does “Remove metadata” take out?+

The document's title, author and other info fields, XMP metadata, embedded page thumbnails and private editing data that apps such as Illustrator store in the file. It's on by default and doesn't change the pages. Turn it off if you need to keep the title and author.

Can I compress a scanned PDF and keep it searchable?+

Strong mode turns pages into plain images, so any text layer is lost. Compress first, then run the smaller file through PDF OCR (tools.northlane.live/pdf-ocr/) to add searchable text back. Lossless clean-up keeps an existing text layer as it is.