PixFlow · Conversion

Convert an image, without the surprises

An image format buys you either compatibility or small file size, rarely both. Picking the right one avoids most problems outright. Every conversion runs in your browser — nothing is uploaded.

Make it readable everywhere

Make it lighter for the web

Build a document

Which format to pick, and why

There is no best format in the abstract, only a format suited to each job. Here is what actually separates the five common ones.

FormatStrengthsAvoid when
JPGReadable everywhere, light on photographs.You need transparency or perfectly crisp text.
PNGLossless, transparency, sharp text.The image is a photograph — the file size explodes for nothing.
WebP25 to 35 percent lighter than JPG, lossy or lossless, transparency.You must deliver to older software or a closed platform.
AVIFThe most efficient on size, handles transparency.Compatibility comes first — support outside browsers is still thin.
HEICVery efficient, native on iPhone.You leave the Apple ecosystem. Convert it every time.

What a conversion will never do

This is the most widespread misunderstanding: converting does not improve an image. If your JPG was compressed too hard and shows artefacts, converting it to PNG produces a heavier file containing exactly those same artefacts. The format is a container; it does not recreate lost information.

Likewise, enlarging does not invent detail, and moving from one lossy format to another adds a generation of degradation. Always start from the file closest to the original source.

Converting to JPG removes transparency: transparent areas turn white. If you need it, target PNG or WebP instead.

Why this all happens in your browser

Conventional online converters upload your files to their servers. For a holiday snapshot that hardly matters. For a scanned ID, a contract or a bank statement, it is a data transfer nothing justifies.

PixFlow converts locally, using the Canvas API and WebAssembly. Nothing to upload, so no wait tied to your connection speed; no volume limit imposed by a server; and documents that never leave your machine. Once the page has loaded, conversion works offline.

Frequently asked questions

Does converting an image improve its quality?

No. A conversion cannot restore information that is already gone. Converting a heavily compressed JPG to PNG gives you a much larger file containing exactly the same flaws. Conversion changes the container, not the content: it serves compatibility or file size, never repair.

Why won't Windows open my HEIC photos?

HEIC has been the default iPhone format since iOS 11. Windows cannot read it without a paid extension from the Microsoft Store, and many websites reject it on upload. Converting to JPG solves this permanently, since JPG is readable by every operating system and virtually every application.

What happens to transparency when I convert to JPG?

It is lost. JPG has no alpha channel, so transparent areas turn white. If you need to keep transparency, convert to PNG or WebP instead — both support it.

Are my files uploaded to a server?

No. Conversion happens entirely in your browser through the Canvas API and WebAssembly. No file leaves your device and nothing is stored. That matters most for scanned documents and personal photographs.

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