How do I reduce the size of a PDF?

Choose Smaller pictures, text stays text and a strength, then press Make smaller. The pictures inside the PDF are made smaller and saved again as JPEG at a lower quality. Pictures are what make most PDFs big, so this is the way that keeps everything else as it was.

Will the text still be selectable after compressing?

With Smaller pictures, text stays text: yes. The text, fonts and links are not touched. With Turn every page into a picture: no. Each page becomes a picture, so the text cannot be selected or searched and links stop working. The page tells you which of the two was used for each file.

Why did my PDF not get smaller?

A PDF made of text and vector graphics has few pictures to compress, so there is little to save. A file may also hold pictures in forms this tool leaves alone, such as black-and-white scans or very small images. Try Turn every page into a picture if you do not need the text, or a stronger setting.

What do Low, Medium and High do?

For pictures, Low keeps them at up to 2400 pixels on the long side at JPEG quality 85, Medium 1600 pixels at 70 and High 1000 pixels at 50. For pages drawn as pictures, Low draws at 150 dpi, Medium at 120 and High at 96. A higher strength gives a smaller file and a softer picture.

No. The file is read and rewritten in your browser, and nothing is sent to a server.

Can it compress a PDF with a password?

Not directly. Open it in a PDF viewer, enter the password, and save a copy without it, then compress that copy.

Is the quality loss visible?

At Low it is hard to notice for photos. At High, fine detail and small text inside pictures become softer. Look at the result before you use it for something important, and keep the original.

Compress PDF Online Free, No Upload

How to use

Choose or drop one or more PDF files. A PDF with a password has to be unlocked first.
Choose how to make it smaller. Smaller pictures, text stays text re-compresses the photos and scans inside the PDF and leaves text, fonts and links alone. Turn every page into a picture draws each page and builds a new PDF from those pictures, which is often the smallest result but removes selectable text.
Choose the strength: Low keeps the best quality, High makes the smallest file. Press Make smaller.
Each file shows its size before and after and what was done. Download it, or download several as a ZIP. If the file could not be made smaller, the original is kept and you are told.

Examples

A 6-page report with 12 photos (11.8 MB), Smaller pictures, Medium

→ 0.37 MB, 97% smaller, text still selectable

Measured with a test PDF made for this page: photos of 3000 by 2000 pixels, shown at the width of a page. Photos from phones are about that size, so expect a similar saving, but a real file can differ.

A 30-page text-only PDF (20 KB)

→ No change: the original is kept

Text and fonts are already small, so there is nothing worth compressing.

A 6-page JPEG scan (3.6 MB), Smaller pictures, Medium, or Turn every page into a picture, Medium

→ 1.03 MB (71% smaller) or 0.83 MB (77% smaller)

For a scan the two ways give a similar size. Smaller pictures keeps any hidden text layer from OCR; turning pages into pictures removes it.

How it works

A PDF is a container. Text and drawings are stored as instructions, and pictures are stored as separate objects, most often as JPEG data. Photos and scans are usually most of a PDF’s size, so shrinking those gives most of the saving.

The Smaller pictures method opens the file with the pdf-lib library, finds every picture object, and for each one that is a photo-sized JPEG or a large lossless picture in RGB or gray, decodes it, makes it smaller if it is larger than the strength allows, and encodes it again as a JPEG at the chosen quality. A picture that would not come out smaller is left as it was, and so are small pictures, stencil masks, black-and-white scans and other forms this tool does not handle. See-through parts of a picture are kept, because the separate mask that describes them is not changed. The file is then saved again with its objects packed together, which also saves a little on its own. If the result is not smaller than the original, the original is kept.

The Turn every page into a picture method draws each page with pdf.js, saves it as a JPEG at the chosen resolution and builds a new PDF in which each page is that picture at the original page size. Because the page is now a picture, text in it cannot be selected, searched or copied, links no longer work, and a hidden text layer added by OCR is lost.

Size savings depend on the file. These were measured in a real browser with test PDFs made for this page: six pages with twelve photos of 3000 by 2000 and 2400 by 1600 pixels (11.8 MB), six JPEG scan pages (3.6 MB), four lossless scan pages (10.3 MB) and a 30-page text-only PDF (20 KB). The photos and scans were drawn by a script, with grain added, so they stand in for real ones.

Test file	Smaller pictures: Low	Medium	High	Pages as pictures: Low	Medium	High
12 photos, 11.8 MB	3.42 MB	0.37 MB	0.13 MB	0.53 MB	0.22 MB	0.13 MB
JPEG scan, 3.6 MB	3.12 MB	1.03 MB	0.43 MB	1.70 MB	0.83 MB	0.45 MB
Lossless scan, 10.3 MB	1.95 MB	0.68 MB	0.28 MB	1.14 MB	0.55 MB	0.30 MB
Text only, 20 KB	no change	no change	no change	no change	no change	no change

At Low the JPEG scan hardly changes (12% smaller), because its pictures are already near that quality and size. Text stayed selectable with every Smaller pictures setting, and it was gone with every Pages as pictures setting that made the file smaller. As a check of readability, the JPEG scan at High, run through the Image to Text tool, read almost as well as the original: 1,885 of its 1,890 words matched the real text, against 1,889 for the original. Real files vary, so check the result before replacing the original.

Which PDF compression option should you choose?

Reports, contracts and searchable PDFs: use Smaller pictures so text, links and the OCR layer remain usable.
Scans for e-mail or upload limits: try Medium first; use Pages as pictures only when the smallest file matters more than selectable text.
Input and output: the input and download are both PDF. Password-protected files must be unlocked first.
Privacy and limits: processing stays on this device. Compression cannot help much when a PDF is already small or contains mostly text and vector drawings; always keep the original until you have checked the result.

Sources

Frequently asked questions

How do I reduce the size of a PDF?: Choose Smaller pictures, text stays text and a strength, then press Make smaller. The pictures inside the PDF are made smaller and saved again as JPEG at a lower quality. Pictures are what make most PDFs big, so this is the way that keeps everything else as it was.
Will the text still be selectable after compressing?: With Smaller pictures, text stays text: yes. The text, fonts and links are not touched. With Turn every page into a picture: no. Each page becomes a picture, so the text cannot be selected or searched and links stop working. The page tells you which of the two was used for each file.
Why did my PDF not get smaller?: A PDF made of text and vector graphics has few pictures to compress, so there is little to save. A file may also hold pictures in forms this tool leaves alone, such as black-and-white scans or very small images. Try Turn every page into a picture if you do not need the text, or a stronger setting.
What do Low, Medium and High do?: For pictures, Low keeps them at up to 2400 pixels on the long side at JPEG quality 85, Medium 1600 pixels at 70 and High 1000 pixels at 50. For pages drawn as pictures, Low draws at 150 dpi, Medium at 120 and High at 96. A higher strength gives a smaller file and a softer picture.
Is my PDF uploaded?: No. The file is read and rewritten in your browser, and nothing is sent to a server.
Can it compress a PDF with a password?: Not directly. Open it in a PDF viewer, enter the password, and save a copy without it, then compress that copy.
Is the quality loss visible?: At Low it is hard to notice for photos. At High, fine detail and small text inside pictures become softer. Look at the result before you use it for something important, and keep the original.

Version history

1.0.2 2026-10-25 — Adds a practical decision guide covering best-fit uses, inputs and outputs, privacy, quality trade-offs and known limits.
1.0.1 2026-10-25 — Makes the search title and description state the supported task, key formats and privacy benefit more clearly.
1.0.0 2026-10-08 — First release.

Last updated: 2026-10-25

Compress PDF Online: Make a PDF Smaller, No Upload