Pass 01
Rebuild the container
Unused objects, duplicate resources, thumbnails and metadata are removed, and the file is rewritten with compact object streams. Text and vectors are not touched at all.
Up to about 12% on text PDFs
Runs entirely in your browser
Compress a PDF to an exact size.Privately in your browser.
Pick a target, drop your file, and get a PDF that actually meets it. Nothing is uploaded — every byte is processed on your device.
- No uploads
- No account
- No watermark
document.pdf
——Analysing…
Advanced options
Your file stays in this browser tab. Closing it deletes everything.
Compressing your PDF…
0%Preparing…
Large files can take a minute. The interface stays responsive — you can keep scrolling while it works.
That file could not be compressed
No uploadNo sign-upNo watermarkWorks offline
Files never leave your deviceNo uploadsNo accountNo watermarkNo file storageWorks offlineOpen target sizesMeasured output
About Compress PDF AI
Compress PDF Online — Free, Private and Exact
Pick a target, drop your file, and get a PDF that actually meets it. Nothing is uploaded — every byte is processed on your device.
Why Compress a PDF File?
Modern forms and portals are strict about size. A visa application may cap each supporting document at 100 KB. A government form might reject anything over 20 KB. Email systems bounce large attachments, and cloud storage quotas fill up quickly with bloated exports. Compressing a PDF file reduces the byte count so the document meets the limit, uploads faster, and stores more cheaply — without changing what the document says. Compress PDF AI gives you honest, measured results: if a target cannot be reached, you see the smallest achievable size instead of a false promise.
How to Compress PDF Files Without Uploading Anything
Because every step happens in your browser, you can compress pdf free without ever sending a document to a third party. The workflow takes under a minute: choose a target size such as 50 KB, 200 KB or 500 KB, drag your PDF onto the dropzone, and let the compressor rebuild the file, recompress images and measure the result. When the output meets your target, download it. You can retarget as many times as you like without re-uploading, and you can prove the privacy claim yourself by turning off Wi-Fi after the page loads — the tool still works.
Compress PDF File Size to Exact Limits (20 KB to 1 MB)
Not every document needs the same limit, and Compress PDF AI covers the most common ceilings. Use 20 KB for single-page government forms and signature sheets. Use 50 KB for one-page resumes and admit cards. Use 100 KB for visa documents, transcripts and statement-of-purpose uploads. Use 200 KB for application packets that include a photo. Use 500 KB for email attachments and brochure uploads. Use 1 MB for photo-heavy portfolios and multi-page reports where quality still matters. Each target has a dedicated page explaining what is realistic at that size, so you know before you start whether compress pdf to 20kb, compress pdf to 50kb, compress pdf to 100kb, compress pdf to 200kb, compress pdf to 500kb or compress pdf to 1mb is the right choice for your file.
Compress PDF Free — No Account, No Watermark, No Upload
Many online compressors hide the file behind a sign-up wall, add a watermark, or store your document on a server you cannot control. Compress PDF AI does none of that. It is free compress pdf software with no account required, no email collected, no tracking scripts, and no watermark injected into your document. You do not even need to stay online: once the page has loaded, you can disconnect and still compress a PDF file because nothing leaves your device.
Client-Side Compression Keeps Your Documents Private
The compressor reads your PDF into the tab's memory using standard browser APIs, rebuilds it with pdf-lib, re-encodes images through the Canvas API, and writes the result back as a local download. PDF.js parses the document and classifies pages so the engine knows whether to use structural cleanup, image recompression or rasterisation. Your file never traverses the network, which means there is no server to breach, no deletion policy to trust, and no copy of your document sitting in anyone's logs. For contracts, ID scans and personal records, this is the safest way to compress pdf online.
Which Target Size Should You Choose?
Start with the smallest limit the portal accepts, then move up only if the result is unreadable. A text-only one-pager can usually reach 20 KB or 50 KB. Documents with a logo or signature fit 100 KB. Application packets with photos land around 200 KB. Brochures and scanned bundles need 500 KB or 1 MB to stay sharp. Compress PDF AI shows the measured byte count after every attempt, so you can pick the highest-quality result that still fits — whether that means compress pdf to 1mb for legibility or compress pdf to 50kb for a strict upload form.
Honest Limits and Realistic Expectations
Compression works best on images, not text. A document that is already mostly text will shrink only slightly because there is little redundant data to remove. Scanned pages and photographs shrink the most, but heavy downscaling softens fine print. Compress PDF AI never rounds down or estimates: a target is marked met only when the measured output is at or below the limit. If your target is impossible, you get the smallest real result with a clear explanation, so you never submit a file that fails.
Ready to compress a PDF? Drop your file on the compressor, choose 20 KB, 50 KB, 100 KB, 200 KB, 500 KB or 1 MB, and download a smaller document — no upload, no account, no watermark. Start with the 100 KB preset or pick your own target and see exactly how small your file can get.
Why this one is different
Your file never leaves the tab.
Every other compressor you have used asks you to upload a private document and trust a deletion policy. This one has nothing to delete, because nothing is sent. Turn off your Wi-Fi after the page loads and it still works.
0 B
Uploaded
There is no backend for file processing. The only requests this site makes are for its own pages and assets.
100%
On device
Reading, recompressing and rebuilding all happen inside your browser using PDF.js, pdf-lib and the Canvas API.
1:1
Measured
Every attempt is saved and measured. A target is only marked as met when the real byte count is at or below it.
6
Presets
20 KB, 50 KB, 100 KB, 200 KB, 500 KB and 1 MB, plus any custom limit you need for a stubborn upload form.
Under the hood
Three passes, from least to most destructive.
The compressor stops as soon as your target is met, so it only reaches for the heavy tools when the gentle ones are not enough.
Pass 02
Recompress the images
Embedded JPEGs are decoded, scaled down and re-encoded at a quality the target can afford, then written back into the original layout. Text stays selectable.
The main workhorse
Pass 03
Rasterise, carefully
For scans — or when nothing else fits — pages are rendered at a lower DPI and rebuilt as images. This is the only path that loses selectable text, and the result tells you when it happens.
Last resort
- 01
Choose a target
Pick a preset or type an exact limit in KB or MB.
- 02
Drop the PDF
The file is read locally and its pages are counted.
- 03
Let it measure
Each strategy is tested and the real output size is checked.
- 04
Download
Save the result, or try another target without re-uploading.
Target size guides
Pick the limit you have to hit.
Each guide explains what is realistic at that size, which file types fit, and how to avoid a rejected upload.
Privacy, quality and impossible targets
The honest answers to the questions people ask before trusting a compressor with a passport scan.
How can a PDF compressor work without uploading my file?
Modern browsers can parse PDFs, decode images and draw pages on a canvas. This site uses those APIs — PDF.js to read and render, pdf-lib to rebuild, and the Canvas API to re-encode images. Your file is read from disk into the tab's memory, compressed there, and saved back to disk. There is no server component anywhere in the project.
Is the compression real, or does it just rename the file?
It is real. The tool rebuilds the PDF with compact object streams, re-encodes embedded JPEG images at lower resolution and quality, and as a last resort renders pages to images at a lower DPI. After every attempt it measures the generated bytes and compares them to your target.
What happens if my target is impossible?
You see the smallest file the compressor can actually produce, how far above the target it is, and a plain explanation. The result is never labelled as meeting the target unless the measured byte count is at or below it.
Will my text stay selectable?
Yes, unless the document has to be rasterised. Text-based PDFs are compressed by rebuilding the file and re-encoding images, so fonts, links and vectors are untouched. Scans have no text layer to begin with, so rasterising them loses nothing.
Does it work on iPhone and Android?
Yes. The tool uses standard browser APIs and falls back gracefully on devices without OffscreenCanvas. Very large files can hit mobile memory limits, which is why files over 150 MB are flagged before you start.
Can I use it offline?
Once the page has loaded, yes. Turn off Wi-Fi and compress a file — it still works, which is the simplest proof that nothing is being uploaded.
How to compress a pdf
Open Compress PDF AI, choose a target size such as 20 KB, 50 KB, 100 KB, 200 KB, 500 KB or 1 MB, drop your PDF onto the page, wait for the browser to compress it locally, then download the smaller file. Nothing is uploaded.
How to compress pdf files
Select your target size, drop one or more PDFs into Compress PDF AI, let the tool compress each file in your browser, and download the results. Files never leave your device.
How to compress a pdf for free?
Compress PDF AI is free to use with no account, no payment and no watermark. Drop your PDF, pick a target size, compress it in your browser and download the result at no cost.
How to compress a pdf file
Drop your PDF file onto Compress PDF AI, choose the size you need to hit, let the local compressor rebuild the file and recompress images, then download the smaller PDF.
How to compress pdf
Use Compress PDF AI: open the page, pick a target limit, drag your PDF onto the dropzone, and download the compressed file once the measured output fits your target.
What does compress a PDF?
Compressing a PDF means reducing its file size by rebuilding the file structure, stripping unused metadata and objects, and recompressing embedded images at lower resolution or quality, while keeping text selectable whenever possible.
How can I compress files?
For PDFs, use Compress PDF AI. Drop the file, choose a target size, and download the compressed version — all processing happens in your browser with no upload required.
How can I compress my PDF document?
Open Compress PDF AI, drop your PDF document onto the page, select a target size such as 100 KB or 500 KB, and download the compressed document once the tool reports a measured size that fits.
Can I compress a PDF that is already compressed?
Yes. The tool tests each quality level and returns the smallest real result it can produce. If your file is already at or below the target, it returns the file unchanged rather than adding artefacts.
How can I compress a PDF file?
Drop your PDF onto Compress PDF AI, choose your target size, let the browser compress it locally, and download the result. No account, no upload and no watermark.
How do I reduce my file size?
Pick the smallest limit your portal accepts, drop your PDF into Compress PDF AI, and download the compressed result. If the target cannot be reached, you see the smallest achievable size instead.
How can I compress a PDF file to 1 MB for free?
Select the 1 MB target on Compress PDF AI, drop your PDF, compress it for free in your browser with no account required, and download the smaller file once it is verified at or below 1 MB.
How to compress a PDF to 0.5 MB?
0.5 MB is 500 KB. Choose the 500 KB target on Compress PDF AI, drop your PDF, compress it locally, and download the result once the measured output is at or below 500 KB.
Compress the file. Keep the document.
No account, no watermark, no upload step. Just a smaller PDF that still opens.