100% local · no uploads · free

Compress PDF for Email

You hit "send" and the email bounces back: "attachment too large." Gmail caps attachments at 25MB. Outlook allows 20MB. Yahoo gives you 25MB. And that scan of the signed contract is 47MB because the scanner captured it at unnecessary print resolution.

The knee-jerk solution is to upload the PDF to some cloud compressor, wait for processing, download a smaller version, and hope the quality is acceptable. But think about what you just did: you uploaded a confidential document — a contract, a medical report, a financial statement — to a server you have never heard of, just to make it smaller for email.

KuroPDF compresses your PDF right in the browser. Set a target size (try 8MB to be safe across all major email providers), and the engine recompresses embedded images at progressively lower quality until the file fits. Text and vector graphics stay perfectly sharp — only the raster images are touched.

The result is a PDF that emails without bouncing, opens without waiting, and still looks professional. Your document never leaves your device during the entire process.

Compress for email →
  • Files never leave your device
  • No size limits
  • Free, no sign-up

How to compress pdf for email

  1. 1
    Load your PDF

    Drop the oversized PDF into the tool. It is parsed locally and never uploaded anywhere.

  2. 2
    Set target size

    Enter a target like 8MB (safe for all email providers) or 20MB (safe for Outlook). The engine iterates until the output fits.

  3. 3
    Download and attach

    Download the compressed PDF and attach it to your email. Text remains selectable and sharp.

Frequently asked questions

What size should I target for email?

For maximum compatibility across Gmail, Outlook, Yahoo, and corporate mail servers: target 8-10MB. Gmail and Yahoo allow up to 25MB, Outlook up to 20MB, but many corporate servers cap at 10MB. Going smaller guarantees delivery.

Will the quality look bad?

For documents with text and a few images, you will rarely notice any difference. The engine only recompresses embedded images — text, charts, and vector graphics remain perfectly crisp. Heavily image-based PDFs (photo albums, scanned documents) show more visible compression, but remain readable.

What if my PDF is mostly scanned pages?

Scanned PDFs are essentially page-sized images, so they compress aggressively. A 50MB scan can often reach 5MB with acceptable quality. Set a comfortable target and preview the result.

Is it safe for confidential documents?

Everything runs locally in your browser using WebAssembly. Because no data is uploaded to a cloud server, your files remain strictly private, and the entire process generates zero server carbon emissions, making it highly eco-friendly.

Can I compress multiple PDFs at once?

The tool processes one PDF at a time. Drop another file immediately after the first finishes for quick sequential compression.

The real difference

Why KuroPDF exists

Every other PDF tool uploads your files to their servers. We think that is broken. Here is what we do differently - and what the alternatives actually cost you.

Nothing leaves your device

Files are processed in your browser using WebAssembly. Open DevTools → Network tab and verify: zero upload requests. Ever.

What competitors do instead:

Smallpdf, iLovePDF, and Adobe Acrobat all upload your files to their servers - your contracts, bank statements, and medical records pass through third-party infrastructure.

No file size limits, no daily caps

Process a 500-page PDF or batch-convert 200 photos. No cap, no throttle, no upgrade wall. Your device is the only limit.

What competitors do instead:

Smallpdf limits free users to 2 tasks per day. iLovePDF caps file sizes at 100MB. Adobe requires a $19.99/mo subscription for basic features.

Works completely offline

Install KuroPDF as a progressive web app. After the first visit, every tool works with zero internet - on a plane, in a bunker, wherever.

What competitors do instead:

Every cloud-based PDF tool stops working the moment your Wi-Fi drops. No connection = no work.

Real encryption, not security theatre

Password protection uses AES-256 encryption via a WebAssembly build of qpdf. The password never leaves your machine - there is no server to intercept it.

What competitors do instead:

When you 'protect' a PDF on Smallpdf or iLovePDF, your unencrypted file and password travel to their server, get processed, then get sent back. That is not security.

Free forever, no account needed

No login wall, no email harvesting, no 'continue with Google' popup. Open the site, use the tool, close the tab. Done.

What competitors do instead:

Adobe charges $239/yr. Smallpdf charges $108/yr. iLovePDF charges $84/yr. All require account creation to use basic tools.

Professional-grade codecs

MozJPEG for JPEG, OxiPNG for PNG, AVIF and WebP encoders - the same codecs used by Google and Mozilla. Not generic re-encoding.

What competitors do instead:

Most cloud tools use basic server-side encoders with less optimization control. You get worse compression at lower quality.

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