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Converts on your device — your PDF is never uploadedReduce PDF File Size
Make a PDF smaller without handing it to a server. The tool inspects your document, tells you how much of it is actually images, then recompresses those images while leaving text and vector graphics untouched. Free, in your browser, no watermark or sign-up.
Find Out Why It Is Big First
Most advice about shrinking PDFs skips the diagnosis, which is why people are so often disappointed. A PDF is large for one of a few reasons, and only one of them is fixable by a compressor:
| Cause | How common | Can compression help? |
|---|---|---|
| Scanned or photographed pages | Very common | Yes — dramatically |
| Embedded photographs and charts | Common | Yes |
| Embedded fonts | Occasional | No |
| Complex vector graphics (maps, CAD) | Occasional | Only by flattening |
| Attachments or revision history | Rare | No |
That is why this tool shows the image share up front. If images are 85% of your file, you are about to save a great deal. If they are 5%, no compressor will rescue it and you should look at how the document was produced instead.
Fix It at the Source Where You Can
Compression is a repair. If you control how the file is made, these prevent the problem entirely:
- Scan at 200–300 DPI, not 600. Text is fully legible at 200; 600 quadruples the data for no practical gain.
- Scan text in grayscale or black and white. Colour triples the data to record paper tint.
- Use a scanning app rather than the camera roll. Document scanners crop, flatten and compress; a raw camera photo does none of that.
- Export rather than print-to-PDF from office software, which keeps text as text instead of rasterising it.
Reducing Size Without Wrecking the Document
The order that works: grayscale first (nearly free for text scans), then resolution (an oversized image is pure waste), then quality (the visible one). Most tools jump straight to quality, which is the setting that costs you the most for the least.
Keep text as text wherever possible. Smart mode never rasterises, so your document stays searchable, copyable and accessible to screen readers — things that are quietly lost when a PDF is flattened into pictures.
Diagnose Before You Compress
The reason so much PDF-shrinking advice disappoints is that it skips straight to the remedy. A 4 MB PDF and another 4 MB PDF can be large for completely different reasons, and only one of them will respond to an image compressor.
A quick self-check: open the PDF and try to select a sentence. If the text highlights, the document contains real text and its size is probably coming from embedded images, fonts or vectors. If nothing highlights, every page is a picture — and image compression will be dramatically effective.
Typical Culprits, in Order
| Symptom | Likely cause | Remedy |
|---|---|---|
| Text cannot be selected | Scanned or photographed pages | Compress images — huge win |
| Few pages, very large file | High-resolution photographs | Compress images |
| Many pages, moderate size | Normal text document | Little to gain |
| Slow to open and scroll | Complex vectors (maps, CAD) | Only flattening helps |
| Large despite plain text | Embedded font subsets or attachments | Re-export from the source |
Prevention Beats Compression
Every compression step is a repair for a decision made earlier. Where you control the source, these four habits mean you rarely need a compressor at all:
- Scan text at 200–300 DPI in grayscale. 600 DPI colour quadruples the data and adds nothing you can see on a typed page.
- Use a document-scanner app, not the camera. Scanner apps crop to the page, correct perspective and compress sensibly; a raw photo does none of that and carries the whole room.
- Export to PDF rather than print-to-PDF from Word, Pages or Google Docs, so text stays as text instead of being rasterised.
- Resize images before placing them. A 12 megapixel photo dropped into a report is carrying roughly forty times the detail an A4 page can print.
What You Lose, and What You Should Refuse to Lose
Compression always costs something — the question is what. Image detail is a reasonable trade for a file that will actually send. The text layer is not: lose it and the document stops being searchable, stops being copyable, and becomes unreadable to screen readers, which may also make it non-compliant with accessibility requirements in an official context.
That is the whole reason Smart mode exists and is the default here. Flattening a document to pixels is the last resort, not the first move.
Frequently Asked Questions
How do I reduce the size of a PDF?
Add the file and the tool immediately reports how much of it is images - the part that can actually be compressed. Choose a target size or a quality level, press Compress, and compare the before and after. Everything runs in your browser.
What actually makes a PDF large?
Almost always images. Text is a few kilobytes per page; a scanned or photographed page is millions of pixels. Embedded fonts, attachments and revision history add some weight, but images dominate in nearly every oversized PDF.
Can I reduce PDF size without losing quality?
Not meaningfully, if the size is coming from images - compression is the saving. What you can avoid is losing the wrong things: Smart mode leaves text and vector graphics untouched, so only the imagery is affected.
How do I know if my PDF can be compressed at all?
The tool tells you as soon as you add it, showing what percentage of the file is images. Below about 25% and there is little to gain from image compression, which the tool warns you about rather than letting you find out afterwards.
Why is my scanned PDF so huge?
Because scanners default to high resolution and full colour. A text page scanned at 600 DPI in colour can be 5 MB; the same page at 200 DPI in grayscale is a fraction of that and just as readable.
Does reducing PDF size affect printing?
It can, if you compress hard. For screen reading and normal office printing, moderate settings are indistinguishable. For professional printing, keep the quality high and accept a larger file.
Is my file uploaded to a server?
No. The PDF is parsed and rebuilt inside your browser and never leaves your device.
Is it free?
Completely free, with no sign-up, no email, no watermark and no daily limit.