Image Converter Online Free

Convert between JPG, PNG, WebP, and BMP image formats, with options for output size and quality. Works for one image at a time.

About this tool

Converting between image formats is essential for web publishing, email attachments, and cross-platform compatibility. You pick the target format in the browser; Pillow on our servers does the encode — including HEIC from iPhones that arrive with the wrong file extension.

How it works

  1. Upload your image file.
  2. Choose your target format: JPG, PNG, WebP, or BMP.
  3. Download your converted image instantly.

Features

Tips for best results

JPG for photos, PNG for screenshots

JPG compresses photographs 5-10× smaller than PNG with no visible loss. PNG keeps sharp edges on screenshots, text, and graphics — JPG introduces ugly halos around hard edges.

WebP is often the right answer for web

If the image is heading online, WebP is usually 25-35% smaller than JPG at equal quality. Every current browser supports it. Skip WebP only if your target is an old platform that still can't decode it.

Transparency only survives in PNG and WebP

Converting a transparent PNG to JPG gives you a solid white background. JPG has no transparency channel. If your image has see-through pixels, keep it in PNG or WebP.

Under the hood

Pillow does the encode, not your browser

The upload is opened with Pillow on the server. JPEG output is written at quality 92 with Huffman optimization. PNG is written with optimize=True. WebP and BMP use Pillow's native encoders. Nothing is re-encoded in JavaScript on your device — the file leaves the browser, comes back converted, and the temp copy is cleaned up with the request.

Transparency is format-aware

A PNG with an alpha channel stays RGBA when the target is PNG. JPEG has no alpha, so those pixels are flattened to RGB (white behind the transparent areas). Other targets that don't carry alpha are also flattened. That is why a logo with a see-through background looks fine as PNG and suddenly has a white box as JPG.

HEIC is decoded from bytes, and truncated JPEGs still open

pillow-heif is registered at server startup, so iPhone HEIC/HEIF opens even when Safari uploaded the raw bytes under a .jpg name. Truncated mobile JPEGs — the ones missing an end-of-image marker after a flaky upload — are decoded instead of rejected, which is the usual failure mode for photos sent from a phone.

Frequently asked questions

What formats are supported for input?

JPG, PNG, WebP, BMP, GIF, TIFF, and iPhone HEIC/HEIF — on every plan.

Which format should I use for web images?

WebP offers the best file size with excellent quality for web use. JPG is the most widely supported for photos. PNG is best for graphics with transparency.

Will I lose quality converting between formats?

Converting to JPG involves some quality reduction as it is a lossy format. PNG and WebP support lossless conversion.

Can I convert HEIC photos from my iPhone?

Yes — HEIC and HEIF formats are supported as input.

What is WebP?

WebP is a modern image format that offers smaller file sizes than JPG or PNG with similar quality — ideal for web use.

Is the conversion done in my browser?

No. The file is uploaded and re-encoded on our servers, then the result is downloaded. The original is not kept as a stored copy.

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