Can I stamp a PDF on iPhone without an app?

Yes. Safari, pick from Files, set text or logo, save to iCloud Drive or Files. Keep the tab open.

How do I do this on Android?

Chrome, pick from Drive or Downloads, overlay, download. Open the result in a PDF viewer to verify.

Why did the phone tab restart?

iOS and Android reclaim memory. Smaller files, close other apps, or use a laptop for big scans.

Does Windows need a store app?

No. Edge or Chrome is enough. Same local Worker as mobile.

Does Safari on Mac work?

Yes. Mac Safari supports the same Instant path. Files never upload.

Can I upload a logo from the camera roll?

If the browser file picker can see the PNG, yes. Export a transparent PNG from your brand kit when possible.

Is mobile stamping less private?

No extra cloud appears because you used a phone. Instant is still local. Only load the page over HTTPS on a network you trust.

Watermark PDF Cluster

Mobile PDF Watermark — Phone, Tablet & Desktop

Field proposal, hotel printer, Android invoice — overlay text or a logo in the phone browser. Keep the tab open until download finishes.

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Workspace

Fast·Converted on our edge network

Image Converters

PDF Tools

PDF Security

Document Converters

Local Tools

JPG to PNG

JPG → PNG·Converted on our edge network

Drag & drop files here

or browse to upload

JPG → PNG

Drag & drop files here

or browse to upload

JPG → PNG

Need the main tool? Watermark PDF

Written by Safaat Rahman Siham, Founder & Developer at Convertify4u. Contact us.

Phones can stamp; they cannot magically hold a 200MB scan

Safari on iPhone and Chrome on Android run the same Web Worker as desktop. Pick a PDF from Files, iCloud, Drive, or Downloads. Type a label or add a PNG. Opacity and grid are touch-friendly. Instant work stays on-device — useful on cellular because you are not uploading a 40MB contract. Huge files, OCR, and multi-hour folders still belong on a laptop with Premium headroom. Keep the tab in the foreground; mobile browsers kill background Workers. No App Store watermark app, no extra privacy policy from a random developer. Windows Edge and Mac Safari use this same URL when you get back to a desk. If iOS asks where to save, choose Files. Android may land in Downloads — open the PDF to confirm the overlay before you present.

Mobile tips

Prefer one-file jobs on cellular. Stable connection is only needed to load the page; after that Instant stamping is local. Do not switch apps mid-process.

When to switch to desktop

Very large scans, many files, or tiny overlay tweaks that need a mouse. Premium batch is a desk job.

How it works

1
Open the browser on phone or desktop
No store install. Safari on iPhone, Chrome on Android, Edge on Windows — same stamper.
2
Pick the PDF and set the overlay
Files, Drive, or local storage. Text or logo, opacity, grid.
3
Save locally
Files or Downloads. Confirm the mark before you walk into the meeting.

Use cases

On-site proposals

Stamp a deck on iPhone before a lobby presentation.

Android invoices

Mark a PDF from email before a client portal upload.

Tablet board review

CONFIDENTIAL on a packet at a hotel printer.

One URL everywhere

Finish on a Mac or Windows machine without learning a second app.

Problems we solve

App Store stampers full of ads

A browser tab avoids another subscription that uploads your files.

Desktop-only layouts

This form is touch-friendly. The same overlay model as desktop.

Cellular upload risk on other sites

Instant local means you are not pushing a large PDF to a remote stamper over LTE.

Trust & privacy

Cross-platform one URL

iPhone, Android, Windows, Mac — one Worker-based tool.

Free mobile singles

Standard phone jobs stay free without signup.

On-device privacy

No Convertify4u copy. No extra native app permissions beyond the browser.

Frequently asked questions

Watermark PDF