PNG to WebP for Client Deliverables: Shrink Files Without Uploading Them (Free)

If you hand off design work to clients, you know the drill: the final package contains a stack of PNGs — hero images, screenshots, exported UI mockups, logo lockups with transparency. They're big, and zipping them doesn't really help. Converting them to WebP cuts the weight dramatically while keeping them pixel-identical for screen use.

There's just one problem. Many designers hesitate to drop client files into a random online converter. Some of those assets are unreleased brand work, under NDA, or contain a client's internal screenshots. Uploading them to someone's server just to shrink a few megabytes is a bad trade. The good news: you don't have to.

Convert PNG to WebP Without Your Files Leaving the Browser

The conversion itself happens in your browser when you use a tool built that way. Open the png to webp converter, drag your PNGs onto the page, and pick your output quality. WebP supports transparency just like PNG, so logo files and UI overlays keep their alpha channel — check the transparent areas before downloading to confirm.

Nothing uploads. The files are processed with local browser APIs and never touch a server, which is exactly the property you want when the assets belong to a client.

A Practical Handoff Workflow

Here's the workflow I use when preparing a deliverables package:

1. Organize by folder. Keep raw-png/ and webp/ folders. Never overwrite your originals — the client (or you, in six months) may need the lossless masters.
2. Convert in batches. Drop all PNGs from one folder into the converter at once. Batch processing keeps naming consistent, so hero-banner.png becomes hero-banner.webp without manual renaming.
3. Pick quality per asset type. Photographic content looks identical around quality 80. Graphics with flat colors and text can go a bit lower without visible change. When in doubt, zoom to 100% and compare before and after.
4. Verify transparency. If a file has an alpha channel (logos, icons, cutouts), open the WebP output against a dark and a light background. WebP handles this fine, but a quick check beats an embarrassed follow-up email.
5. Ship with a README note. Add one line telling the client the WebP files are the web-ready versions and the PNGs are the masters. Most clients won't know the difference, and it saves support questions later.

Two Mistakes to Avoid

Don't send WebP as the only format for print. WebP is a web format. If the client also needs print materials, keep PNG (or better, a proper print format) in the package. The README note from step 5 covers this.

Don't reconvert the same file twice. Converting PNG → WebP → WebP again compounds quality loss. If you need a different quality level, go back to the original PNG. This is why keeping the masters matters.

One more consideration: some older content systems still refuse WebP uploads. If your client's CMS is one of them, ship both formats and let their system pick. The WebP versions will still be useful the day they upgrade.

Disclosure: I'm the developer of FileOnTap. It's a free set of file converters that run entirely in your browser — no uploads, no accounts. I built it because I was tired of feeding my own client files to server-side converters.