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WebP Converter

About us

WebP Converter is a free image converter that runs entirely inside your web browser. Drop in a file, pick an output format, and get the converted image back — without the file ever leaving your device.

formats read
11
formats written
7
conversion pairs
70
files uploaded
0

Why we built it this way

The typical online converter works by uploading your image to a server, converting it there, and handing back a download link. That design is easy to build and impossible to audit. Your photograph, passport scan, medical image or unreleased product shot sits on somebody else’s hardware, governed by a retention policy you have to take on faith.

It is worth being concrete about what that means. A retention promise is only as good as the company making it, and it does not survive a breach, an acquisition, a subpoena, a misconfigured storage bucket, or an engineer with broad database access and a bad week. None of those require anyone to act in bad faith. They are simply the ordinary risks of a file existing somewhere you do not control.

Browsers no longer make that trade-off necessary. The Canvas API handles the common formats natively, and WebAssembly builds of the same codecs used by desktop tools cover the rest. The conversion that used to justify a server now runs perfectly well in a tab. So we ship the converter to you instead of shipping your file to us — and the entire category of risk above simply does not apply, because there is no copy to lose.

How a conversion actually works

Five steps, all of them on your device:

  1. Read

    The file is read into the memory of your browser tab through the standard File API — the same mechanism that lets a web page show you a preview of a photo before you upload it anywhere.

  2. Decode

    Common formats decode through the browser's own image pipeline. Formats it cannot read — HEIC from an iPhone, TIFF, PDF pages — are handled by WebAssembly builds of the same codec libraries desktop software uses, downloaded only when a file actually needs them.

  3. Draw

    The decoded image is drawn to an off-screen canvas, applying any resize you asked for. Formats without transparency get your chosen background colour painted underneath first, so nothing turns unexpectedly black.

  4. Encode

    The canvas is re-encoded into the format you picked, at the quality you set. BMP and ICO are assembled byte by byte, because no browser will write those containers correctly on its own.

  5. Hand back

    The result becomes a temporary in-memory link that your browser saves to disk. Close the tab and every trace of it is gone.

What that means in practice

  • No upload endpoint. There is no API route that accepts image data, because there is nothing on our side that needs it.
  • No database of your files. We cannot show you your conversion history because we never had it.
  • No staff access. There is no internal tool, dashboard or support screen through which anyone here could look at your images. The capability does not exist rather than being restricted by policy.
  • Nothing to hand over. A request for your files — however official — cannot be complied with, because there is nothing to produce.
  • Verifiable in thirty seconds. Open your browser’s developer tools, switch to the Network tab, and convert something. You will see the page assets load and nothing carrying your file leave.
  • Works offline. Once the page and its codecs are loaded, the conversion itself needs no connection at all. Try it in aeroplane mode.

Who tends to use it

The privacy argument is not abstract for everyone. The people who write to us most often are:

  • iPhone owners whose photos are HEIC files that Windows, older software and half the upload forms on the internet refuse to open.
  • Web developers and designers converting batches of PNGs to WebP or AVIF to get a page under a performance budget.
  • People handling documents that should not be uploaded anywhere — scanned IDs, medical images, legal paperwork, financial statements.
  • Anyone on a locked-down network where sending files to an unknown third-party server is against policy, or simply blocked.

What we support

11 formats and 70 conversion pairs. We read JPG, PNG, WebP, GIF, BMP, TIFF, ICO, SVG, HEIC, AVIF, PDF, and write JPG, PNG, WebP, BMP, ICO, AVIF, PDF. You can browse the full list or start from the universal converter.

Beyond the format itself you get quality control on lossy exports, optional resizing, a background colour for formats that cannot store transparency, batch conversion of as many files as you like, and a ZIP download when one file at a time gets tedious.

What it deliberately does not do

A tool is more useful when it is honest about its edges, so here are ours.

  • GIF, TIFF, SVG, HEIC are read-only. We can open them, but we will not write them. Producing a genuine animated GIF, a multi-page TIFF, or true vector SVG traced from a photograph needs tooling well past what belongs in a browser tab, and a bad imitation of any of them is worse than an honest no.
  • Animation is not preserved. Converting an animated GIF to a still format gives you the first frame. That is what almost everyone wants from that conversion, but it is worth stating rather than surprising you.
  • There is a 50 MB ceiling per file. Conversion happens in your tab’s memory, and very large images can exhaust it — especially on phones. We would rather refuse a file than crash your browser with it. The number of files is unlimited.
  • Results vary slightly by browser. Encoders are the browser’s, not ours. AVIF in particular is fast where the browser supports it natively and slower where we fall back to a WebAssembly encoder.
  • We cannot recover anything. No history, no re-downloads, no support ticket that retrieves last week’s file. That is the direct cost of holding nothing — keep your originals until you have checked the output.

What we believe

Your files are yours

The only defensible amount of your data to hold is none. So the converter is delivered to you and runs on your machine, rather than your file being delivered to us.

Claims you can check

"We delete your files after an hour" is unverifiable. "Nothing was ever sent" is something you can confirm yourself in thirty seconds with the Network tab open.

No dark patterns

No account wall before the download. No watermark you pay to remove. No daily quota that appears on your fourth file. No newsletter box between you and the result.

Honest about limits

Some conversions are lossy, some are impossible in a browser, and some depend on which browser you use. We would rather say so plainly than quietly return a worse file.

How it stays free

Because there is no server-side image processing, running this site costs almost nothing — it is static files on a CDN. There is no per-conversion expense to recover, which is precisely why there is no paid tier and no conversion limit. A converter that costs us nothing per use has no reason to ration it.

We may show unobtrusive advertising or use privacy-friendly analytics to cover hosting. Neither ever gets access to your images: they run in the page, and your file never becomes part of the page’s data. Our Privacy Policy spells out exactly what is and is not collected, and the Cookie Policy lists every piece of storage we touch.

Where it is going

The things we are most often asked for, roughly in the order we would like to build them: a compression mode that shrinks a file without changing its format, bulk resizing as a first-class tool rather than a checkbox, basic crop and rotate before conversion, and offline installability so the converter keeps working with no connection at all. None of these require changing the architecture, which is the point — everything above is possible precisely because the work already happens on your device.

Get in touch

Found a file that will not convert, or a format you wish we handled? Write to us at hello@webpconvert.cloud or use the contact form. Telling us the format, the rough file size and which browser you were using turns most bug reports into a fix rather than a conversation.