Compress PDF
Reduce your PDF file size. Choose a quality level to balance size and visual clarity.
Drop your PDF here, or click to select
Single PDF file · Max 100MB
Shrink a heavy PDF down to a size you can actually send
Most oversized PDFs are not heavy because of their text — a 40-page contract of pure type rarely breaks a megabyte. The weight almost always comes from images: a scan where every page is a full-resolution photograph, a brochure exported at print DPI, or a deck of pasted screenshots. This tool targets exactly that — it finds the embedded image data and re-encodes it, where the savings live.
When file size is the thing blocking you
- Email and form attachment caps. Gmail stops at 25 MB, many corporate mail servers at 10 MB, and bank or government upload forms often refuse anything over 5 MB. A scanned 20-page PDF can blow past all three until you compress it.
- Scans from a phone or copier. "Scan to PDF" apps and office copiers tend to embed images at 300 DPI or higher. Smart mode downsamples those to a screen-readable resolution and re-encodes them as JPEG — usually the single biggest win you can get.
- Decks and brochures for the web. A download shrinks a lot once its photos are recompressed, and bulk-trimming hundreds of invoices keeps a shared drive from ballooning.
Smart vs. rasterize, and why it matters
Smart mode (the default) walks the PDF's image XObjects, downsamples and re-encodes each one, and leaves the page structure and text layer untouched. Your text stays vector-based — crisp at any zoom, selectable, and searchable. Use it unless you have a reason not to.
Rasterize mode is the heavier hammer: it flattens every page into a single JPEG, collapsing fonts, vectors, and images into one flat picture. The file gets as small as it can, but the text is now pixels you can't select, search, or copy. Reach for it only when smart mode hasn't shrunk things enough and you don't need the text to be live (say, a read-only flyer).
The quality choice (high / medium / low) controls how aggressively images are recompressed and downsampled — higher keeps more detail and saves less, lower does the opposite. The tool shows before/after byte counts and percent saved the moment it finishes, so treat the first pass as a measurement: if it's not small enough, drop a level and run it again.
Practical tips
- A mostly-text PDF won't shrink much — there's little image data to squeeze. That's expected.
- Image compression is lossy: a lower quality discards detail you can't get back, so keep your original.
- If a single file is too large to upload, split it first and compress the parts separately.
When a different tool is the right move
- [Resize PDF](/resize-pdf) changes physical page dimensions (A4 to Letter) — use it when the layout is wrong, not when the file is heavy.
- [Split PDF](/split-pdf) carves a document into ranges; pulling out just the pages you need is often a bigger size win than compressing the whole thing.
- [PDF to Images](/pdf-to-images) exports each page as a standalone PNG or JPEG, for when you want pictures rather than a smaller PDF.
How it works
- Drop your PDF onto the upload area or click to browse for it.
- Choose smart or rasterize mode and set the quality slider.
- Click Compress and compare the before and after file sizes.
- Download your smaller PDF in seconds.
Frequently Asked Questions
What is the difference between smart and rasterize mode?
Smart mode walks the PDF's embedded image XObjects, downsamples and re-encodes them as JPEG, and leaves the page structure and text layer untouched, so text stays vector-sharp, selectable, and searchable. Rasterize mode flattens each page into a single JPEG for maximum shrinkage, but the text becomes pixels you can no longer select, search, or copy.
Why did my PDF barely change after compressing?
There was little image data to squeeze. A text-heavy PDF, or one whose images are already optimized, is close to as small as it sensibly gets in smart mode. The before/after readout confirms how much was actually saved.
Does compressing twice make the file even smaller?
Rarely, and it can hurt quality. Re-compressing already-recompressed JPEGs mostly adds artifacts for little gain. If the first run wasn't enough, lower the quality and compress the original once rather than stacking passes.
Why does compression mostly shrink scans and image-heavy PDFs?
The weight in most oversized PDFs is embedded image data, not text, so that is where the savings live. Phone scans and copier output are often embedded at 300 DPI or higher, and smart mode downsamples those to a screen resolution, usually the single biggest win.
Does the quality setting affect text sharpness?
No. The high/medium/low quality choice only controls how aggressively embedded images are recompressed and downsampled. In smart mode the text layer is never touched, so text stays crisp at any zoom regardless of the quality level.
How do I compress a PDF to 100 KB or under a specific size?
Run smart mode at low quality first — for a typical scanned page or two that alone often lands under 100 KB. Still too big? Switch to rasterize mode at low quality for maximum shrinkage, and delete any pages you don't need before compressing. A hard size cap usually comes from upload forms; the before/after readout shows exactly what you achieved so you can adjust and re-run from the original.
What is the largest PDF I can compress?
Up to 100 MB per file, within a 500 MB total request. If a single file is too large, split it first and compress the parts separately.