Drop your PDF files here
or click to browse · Up to 20 files at once
PDFMax ~100MB per file
No upload · 100% private
All tools
Proton protects mail after attach — this page protects the compress step. Locked Web preset, ~25 MB checker, pixels stay in your tab until you attach in Proton.
Drop your PDF files here
or click to browse · Up to 20 files at once
Proton Mail encrypts a message on its own infrastructure after you attach, which is excellent — right up until you realise you fed the same PDF to a public “free compressor” minutes earlier. That first upload quietly creates a processor who was never supposed to touch the exhibit. This page deletes that hop entirely.
Signed agreements, medical letters, and evidence bundles are re-encoded in tab memory and never transit our servers. You download the trimmed copy, then attach it inside Proton like any other file.
Annotations remain switched on by default so counsel comments and redline notes survive the shrink. Close the tab afterwards and there is nothing on our side to close.
Encryption does not repeal file-size reality. Free and many Plus workflows still feel a practical 25 MB comfort zone for everyday attachments, so a dense scanned exhibit will refuse to attach no matter how private the mailbox is.
Faced with that, privacy-conscious users often defeat their own choice by pasting the document into a random compress host — the exact behaviour Proton was chosen to avoid. A local Web preset with a live gauge keeps the whole chain on the device.
This page exists to resolve that contradiction: privacy-preserving compression feeding a privacy-preserving inbox, with no third party in the middle.
| Problem it solves | Proton attachment too large / privacy-safe shrink |
|---|---|
| Size check | 25 MB before download |
| Preset | Web · 96 DPI · 59% JPEG |
| Annotations | Preserved for counsel markup |
| Privacy | Local only before the Proton attach |
| Related tools | Yahoo Mail · Box |
Legal and security reviewers annotate before they send, so wiping comment streams by default would quietly destroy the point of the message. This profile keeps every annotation intact while still shedding the image bulk that inflates scanned bundles.
The JPEG quality sits at 59, a touch firmer than a plain webmail target, because Proton correspondents tend to ship dense exhibit scans that need a little extra squeeze. It stops short of grayscale homework mode so seals and signatures stay convincing to a human reviewer.
Proton’s guarantees begin the instant a message leaves your client. Anything you did to the file beforehand — including a detour through an unknown compressor — sits outside that shield, which is why the shrink belongs on your own machine.
Reach for the Yahoo Mail page only when the destination is actually a Yahoo inbox, since its preview quirks differ from Proton’s. For enterprise reviewers who need a hosted copy after mail proves too tight, hand the bundle to the Box page and keep annotations attached.
Truly archival packets should stay untouched offline; send a Proton Drive link rather than grinding vector text into mush with repeated passes. When one exhibit alone is enormous, isolate it with Split PDF first.
For a one-off manual quality tweak, the unlocked Compress PDF hub and the wider PDF tools catalogue cover the rest.
I keep this page because PDF attachment limits for Proton Mail kept failing with upload tools or generic presets. Here you pick the Screen/Web preset that fits the channel, compress locally, then attach. Limits and architecture are documented in Lab Notes — this URL is a micro-instrument for one job, not a keyword clone.