Compress PDF Online Free — Reduce PDF Size Without Losing Quality
Compress PDF online free to a target size like 100KB, 200KB or 1MB, or shrink it without losing quality. Runs 100% in your browser - your PDF is never uploaded.
Select PDFs to compress
Drag & drop one or many PDFs, or click to browse
Batch compression is supported — every file is processed on your own device
Files never leave your device
Processed entirely in your browser — nothing is uploaded
No account required
No sign-up, no email, no usage counter
No file size limit
Bounded only by your own device memory
No watermarks
Your output comes back clean and unbranded
Every engine on this page runs inside your browser tab — your PDFs are never uploaded, so there is nothing on our side to delete.
How to compress a PDF file
- 1
Add your PDFs
Drop in one file or a whole batch. Each one shows its real size and page count before anything happens.
- 2
Choose how hard to squeeze
Lossless keeps text as text. Balanced and below re-encode page imagery — or set an exact target size and let it find the settings.
- 3
Check the before/after and download
You get the original and compressed page side by side with the exact saving, so you can re-run at a different level if the trade-off isn't right.
About this tool
This compressor shrinks oversized PDFs in your browser, with no upload step at any point. It offers two honest engines instead of one mystery button: a lossless pass that rewrites the file structure and strips metadata while leaving every pixel and every glyph untouched, and an image pass that re-encodes page imagery at a resolution you choose — which is where the 70–90% reductions on scanned documents actually come from. It exists for one recurring headache: an upload form, email server or application portal rejecting your file for being a few megabytes over its limit.
How to Compress a PDF File
- 1
Add one PDF or a whole batch. Each file's original size and page count are read locally and shown straight away, so you have a baseline to measure the saving against.
- 2
Choose how hard to squeeze. Lossless cleanup keeps text selectable and images pristine. Balanced re-encodes pages at 150 DPI and suits almost everything. Strong and Maximum go further for strict size caps, and Custom hands you the DPI and JPEG quality sliders directly. You can also name a target size and let the tool find settings that fit, convert to grayscale, or strip document metadata.
- 3
Compress and compare. Every file shows its original and compressed first page side by side with the exact byte counts and percentage saved, so you can judge the trade-off with your own eyes and re-run at a different level if it is not right. Download files individually or grab the whole batch as a ZIP.
Why Compress PDFs with Wrklyst
- Nothing Is Uploaded, Ever
- Compression runs in your browser tab. Your document never reaches a server, so there is no transfer to secure and no temporary copy whose deletion you have to take on faith.
- You Choose the Trade-Off
- Most tools hide the quality decision behind a single button and hand back a blurry contract. Here the lossless and image engines are labelled plainly, and you see the result before you download it.
- Real Before-and-After Proof
- Each file shows its original and compressed page rendered side by side with exact sizes. No guessing whether that 82% saving cost you the small print.
- Target a Specific Size
- Say 'get under 1 MB' and the tool retries at progressively lower resolution and quality until the file fits, then tells you honestly if it could not get there.
- Batch, Then Download as ZIP
- Queue as many PDFs as you like, compress them in one run with the same settings, and download the whole set as a single archive.
- Never Bigger Than You Started
- If every setting produces a larger file than the original — which happens on PDFs that are already well optimised — the tool says so and returns your original untouched.
Why Compress PDF Files?
- Email attachment limits
- Gmail, Outlook and most corporate mail servers reject attachments over roughly 25 MB. Scanned contracts and design exports blow past that constantly, and compressing is faster than uploading to a file-sharing service and sending a link.
- WhatsApp and messaging limits
- WhatsApp caps documents at 100 MB and other messengers are stricter still. A compressed PDF sends immediately instead of failing halfway through on a mobile connection.
- Website and portal upload limits
- Job boards, visa portals, university applications and tax filing sites routinely enforce 2 MB or 5 MB per document. Targeting an exact size is the difference between submitting on time and refreshing a rejected form.
- Faster loading for readers
- A PDF you host or share is downloaded by every reader. Cutting it from 40 MB to 4 MB removes the wait before anyone can see page one, which matters especially on mobile data.
- Saving storage and backup space
- Archives of scanned records are dominated by image data stored at far higher resolution than anyone will ever view. Compressing a whole folder can reclaim most of its footprint without losing legibility.
- Printing and sharing scans
- Phone scanner apps save at print resolution by default. If a scan only needs to be read on screen, re-encoding at 150 DPI keeps it perfectly legible at a fraction of the size.
How Much Can You Compress a PDF?
The honest answer depends entirely on what is inside the file. Compression removes redundancy, and different PDFs have wildly different amounts of it to give up.
| Method | Verdict | What that means |
|---|---|---|
| Scanned PDFs | Typically 60–90% smaller | Scanners save page images at 300 or 600 DPI regardless of need. Re-encoding at 150 DPI, or grayscale for black-and-white originals, removes an enormous amount of data with no visible change on screen. |
| Image-heavy PDFs | Typically 50–70% smaller | Brochures, presentations and design exports embed photographs at full resolution. Downsampling them to the size they are actually displayed at is where the saving lives. |
| Text PDFs from Word or LaTeX | Usually 5–20% smaller | Text is stored as compact vector instructions and is already efficient. The lossless pass reclaims metadata, accessibility trees and editor scratch data — real but modest, because there is little fat to trim. |
| Already-compressed PDFs | Little or nothing | A file that has been through a compressor once has no redundancy left. This tool detects that case, tells you the original was already optimal, and gives it back rather than pretending to have helped. |
Pro Tips for Compressing PDFs
- Try Lossless cleanup first. If it gets you under the limit, you have lost nothing at all — only move to the image engine if you still need more.
- For black-and-white scans, turning on grayscale often saves another 30–40% with no perceptible difference, because the colour channels held nothing useful.
- Use the target size option when a portal enforces a hard cap. It ladders down through resolution and quality automatically instead of making you guess.
- Always look at the side-by-side preview before downloading — it takes two seconds and catches the case where the small print has gone soft.
- If a compressed file comes back barely smaller, the PDF was already optimised. Compressing again will not help; splitting out the pages you actually need will.
- Compressing a merged document is usually more effective than compressing each part first, since duplicate embedded fonts and images can be shared across the whole file.
Frequently asked questions
How do I compress a PDF without losing quality?
Choose the Lossless cleanup preset. It rewrites the document's internal structure using object streams and removes metadata, accessibility trees and editor scratch data, without touching a single pixel or glyph — text stays selectable and images keep their original resolution. The saving is modest, usually 5–20%, because that is genuinely all the waste a well-formed PDF contains. Any tool promising a 90% reduction with 'no quality loss' is re-encoding your images and not telling you; we label that as the image engine and show you the result first.
How much can I reduce a PDF file size?
Scanned documents routinely drop 60–90%, because their page images are stored at far higher resolution than a screen can display. Image-heavy brochures and presentations typically fall 50–70%. A text-only PDF exported from Word might only lose 5–20%, since text is already stored efficiently. If a file barely shrinks, that is usually good news: it means it was already well optimised.
Is there a limit to PDF file size?
We set no limit. Since compression happens on your own device, there is no upload quota and no per-file cap — the constraint is your device's memory. Note that the image engine renders each page to a canvas, which is memory-hungry at high DPI: on a phone, a 500-page document at 300 DPI may run out of memory, and lowering the resolution or splitting the file solves it.
Will compression affect text readability?
With the lossless engine, no — text is not touched at all and remains crisp at any zoom level. With the image engine, text becomes part of a page image, so readability depends on the resolution you pick. At 150 DPI, body text is comfortably readable on screen and prints acceptably. At 72 DPI, small print and footnotes start to soften noticeably. This is exactly why every result shows you the compressed page next to the original before you commit to downloading it.
Can I compress multiple PDFs at once?
Yes. Drop in as many files as you like and they are queued as a batch, compressed one after another with the same settings, and reported individually with their own before-and-after sizes. Once the run finishes you can download each file separately or take the whole set as a single ZIP archive. The summary line also shows the total saving achieved across the batch.