Compress PDF
Make a PDF smaller without sending it anywhere. Each page is redrawn at the resolution you pick and written into a new PDF in this tab — the text on those pages becomes an image, which is the price of the big savings.
Drop a PDF here
or choose a file · one PDF at a time, up to 60 pages · or paste one with Ctrl + V
PDF in, smaller PDF out · up to 60 pages · 72–300 DPI · target a size in KB or MB · no upload · no account · no watermark
Compress PDF Without Uploading It
A PDF gets smaller when the pictures inside it get smaller. This page redraws each page at a resolution you choose, saves the result as a JPEG, and writes a new PDF from those pages in your own browser tab. Move a slider and the size changes in front of you; nothing is uploaded at any point.
There is a trade-off, and it is better to hear it before you start.
The text on those pages becomes part of a picture. It still looks like text, but you cannot select it, search it, copy it, or have a screen reader read it back. If the document has to stay selectable, keep the original and use a tool that leaves the text alone.
What is actually holding the size up
A PDF page can hold two very different things: instructions for drawing text and lines, or a photograph of the page. Instructions are cheap. A page of type is drawing instructions plus a font, and it weighs tens of kilobytes. A photograph of the same page at scan resolution weighs hundreds of kilobytes.
That is why the same settings behave so differently on different files:
- A scanned page is one large image. Every pixel of the paper is stored, including the blank margins. Shrinking that image shrinks the file, and this is where compression earns its keep.
- A born-digital page is text plus whatever images were pasted in. The text part is already efficient, so the only way to cut the size is to throw information away: fewer pixels per page, or harsher JPEG quality.
Five seconds to tell which one you are holding
Three checks, in order of speed:
- Try to select a sentence. If the text highlights and copies, the page holds real text. If the cursor turns into a hand and drags the whole page, it is an image.
- Zoom to 400%. Text that stays sharp is being drawn fresh at every zoom level. Text that turns into coloured blocks is a picture of text.
- Divide the file size by the page count. The 8-page scan used in the table below works out at about 700 KB per page. A page of real text is a small fraction of that. A high number per page means pictures.
Those answers decide what happens next. A scan has room to shrink. A text PDF may not shrink at all, and can grow, which is the case covered further down.
What happens to a page inside this tool
The steps are mechanical, and none of them need a server:
- A PDF renderer, about 1.3 MB, is fetched the first time you convert and cached after that.
- Each page is drawn onto a canvas as pixels. The canvas is
page size × DPI, so an A4 page at 150 DPI becomes 1240 × 1754 pixels. - The canvas is encoded as a JPEG at the quality you picked.
- Those JPEGs are written into a new PDF, one image per page, with the original page dimensions kept.
Keeping the page dimensions matters more than it sounds. A compressed PDF that comes back at a different paper size breaks printing, stamps and anything that expects Letter or A4. Here the page boxes are copied from the source, so a 612 × 792 pt page stays 612 × 792 pt.
What does not survive: links, form fields, bookmarks, tags, document properties, and the text itself. Anything that was not visible on the page was never drawn on the canvas, so it cannot be written back.
The two dials, and which one you actually need
Resolution decides how many pixels a page is drawn with. The arithmetic is pixels = inches × DPI, and a PDF stores page sizes in points at 72 per inch, so the 72 DPI column is the page's own measurements.
| Page size | 72 DPI | 110 DPI | 150 DPI | 200 DPI | 300 DPI |
|---|---|---|---|---|---|
| A4 (8.27 × 11.69 in) | 595 × 842 | 909 × 1286 | 1240 × 1754 | 1654 × 2339 | 2480 × 3508 |
| US Letter (8.5 × 11 in) | 612 × 792 | 935 × 1210 | 1275 × 1650 | 1700 × 2200 | 2550 × 3300 |
Quality decides how hard the JPEG encoder works on the pixels you just produced. It is a size dial, not a detail dial: going from 60 to 90 cannot bring back a letter that was too small to draw at the chosen resolution. Fix resolution first, then quality.
For scans, 150 DPI at quality 75 is a sensible first try: small text stays readable, and in the runs below it cut 75% off an 8-page scan. For text PDFs, that same setting made the file larger, for the reason in the next section.
Measured: three files, nine runs
All runs used this page in desktop Chrome on one laptop, with the files described below. The numbers are what the tool reported, before and after.
| File | Pages | Original | Setting | Result | Change |
|---|---|---|---|---|---|
| Scan, 300 DPI pages | 8 | 5.60 MB | 200 DPI, q80 | 2.38 MB | 58% smaller |
| Scan, 300 DPI pages | 8 | 5.60 MB | 150 DPI, q75 | 1.41 MB | 75% smaller |
| Scan, 300 DPI pages | 8 | 5.60 MB | 110 DPI, q75 | 905 KB | 84% smaller |
| Photo pages, 12 MP each | 3 | 2.74 MB | 200 DPI, q80 | 1.12 MB | 59% smaller |
| Photo pages, 12 MP each | 3 | 2.74 MB | 150 DPI, q75 | 584 KB | 79% smaller |
| Photo pages, 12 MP each | 3 | 2.74 MB | target 200 KB | 171 KB | 94% smaller |
| Text PDF, vector | 15 | 2.11 MB | 150 DPI, q75 | 3.25 MB | 54% larger |
| Text PDF, vector | 15 | 2.11 MB | 120 DPI, q60 | 1.92 MB | 9% smaller |
| Text PDF, vector | 15 | 2.11 MB | 96 DPI, q55 | 1.28 MB | 39% smaller |
Two things stand out. The scan loses three quarters of its weight at a setting where the text is still easy to read. The text PDF gains half its size again at that same setting, because 15 pages of instructions became 15 photographs.
When the rebuilt file comes out bigger
The tool tells you instead of pretending. If the new file is not smaller, the status line says so and suggests keeping the original.
That is the right answer for a PDF like this one. The 2.11 MB paper above is already efficient: its text is instructions, and its figures were compressed once already. Redrawing it at 150 DPI spends about 200 KB per page to store something the file already described in about 140 KB.
If you still need a smaller copy of a file like that:
- Drop the resolution hard. At 96 DPI the same paper came out at 1.28 MB, a 39% cut. It is readable on screen and poor in print.
- Ask the sender for a smaller export. If you exported the PDF yourself, check the export dialog for a "reduce file size" or "compress images" option; that setting does the job without turning text into pixels.
- Split the file. Two halves of 1 MB are easier to send than one of 2 MB when the limit is per message.
Compressing to a size limit
A size limit is a number: under 200 KB, under 1 MB. Picking that number as a target is more reliable than guessing at a quality setting, so the tool can solve it for you.
The budget is split across the pages. With 8 pages and a 1 MB target, each page gets about 125 KB. For each page the tool finds the highest JPEG quality that fits the budget; if even the lowest quality does not fit, it redraws that page at a lower resolution and tries again, down to 72 DPI.
That last fallback is what makes small targets reachable at all. Without it, a dense photo page would sit at 100 KB no matter which quality you chose, because JPEG cannot compress a busy image below a certain point at full size.
It can still miss, and it says so. An 8-page scan asked for 200 KB came back at 258 KB, solved down to 72 DPI. Eight pages at 72 DPI are 4 megapixels of paper, and text at that scale does not compress to 25 KB a page. When that happens, split the document or accept the closest size.
Check the result before you send it
Four checks, about thirty seconds:
- Page count. Open the new file and compare. A page that failed to render would be missing, and the count is the fastest way to notice.
- Zoom to 100% and read the smallest text. Footnotes, table headers, the fine print on a form. That is where a too-low resolution shows up first.
- Look at thin lines and gradients. Charts and signatures are the first things to band or blur, because JPEG works in blocks and a thin stroke sits inside one block.
- Check what you lost. Click a link, tab into a form field, try to select a paragraph. If any of those mattered, you have the wrong tool for this file.
For anything going to a printer, also open the print preview at 100%. A page that looks fine on a screen 1240 pixels wide can be visibly soft on paper.
When to keep the original
Compression here is lossy for anything that was an image, and total for anything that was not. Keep the original when:
- The document must stay searchable or accessible. Tagged PDFs, screen readers and text search all need the text layer.
- It has form fields or signatures that someone still has to fill in or verify.
- It will be printed at quality, where 300 DPI is the usual bar.
- It is a legal or archival copy where the file itself is the evidence.
- It was already compressed once. A JPEG re-encoded a second time loses more than it saves; two rounds of compression look worse than one round at half the quality.
Quick answers
Does it upload my file? No. The file is read from disk by the browser, drawn on a canvas in the tab, and written back as a download. You can confirm it: open DevTools (F12), clear the Network panel, convert a file, and watch the requests. During a conversion the only request we saw was this site's own analytics ping, which carries no file data.
With the renderer already loaded, a run with the network switched off still produced a 905 KB file from a 5.60 MB one.
Is there a page limit? 60 pages per file, and 200 MB. The limit exists because every page is drawn at full resolution in memory: one A4 page at 300 DPI is 8.7 megapixels, about 35 MB of canvas at 4 bytes per pixel.
Can I keep the text selectable and still shrink the file? Not with this tool. Redrawing a page means the text becomes pixels. Tools that preserve text do it by re-encoding the embedded images and leaving the text layer alone, which is a different job with smaller savings on scans.
Why does my PDF stay large? Either the content is vector art and text, which is already compact, or the images inside are already compressed. Check the per-page size first: if it is already small, there is nothing left to win.
What is the smallest my file can go? 72 DPI is the floor here. Below that, body text stops being readable and the savings are smaller than the damage.
Can I compress a password-protected PDF? No. Remove the password first, then compress.
Are my bookmarks and links kept? No. They live outside the page image, and this tool writes only the page images.
Can I do several files at once? One at a time. The output name gets a -compressed suffix so you can tell it from the original.