Image format converter

What the format you pick actually changes

The spread between formats is larger than most people expect. Take a 1920×1080 photo: BMP lands around 6 MB, PNG around 2.5 MB, JPG at quality 85 around 300 KB, WebP at 80 around 220 KB, and AVIF at 80 around 160 KB. Every number in that list is the same image — the container and codec are doing all the work.

BMP
~6 MB
PNG
~2.5 MB
JPG ~85
~300 KB
WebP ~80
~220 KB
AVIF ~80
~160 KB

Feature support splits the formats into clear lanes. Alpha transparency lives in PNG, WebP, and AVIF. Animation lives in GIF, WebP, and AVIF. Lossless modes live in PNG, WebP, AVIF, and TIFF. Wide-gamut/10-bit color is an AVIF and HEIC story. SVG is the only vector format in the mix. Picking the right lane is usually more important than tuning the quality slider.

How to read the quality slider by output format

  • JPEG / lossy WebP / lossy AVIF: higher values preserve more detail and cost more bytes.
  • PNG: lossless pixels — the slider maps to DEFLATE effort (file size vs encode time).
  • TIFF (JPEG compression inside TIFF): behaves like JPEG quality inside the TIFF wrapper.

Default 85 on this page matches most photo-to-lossy workflows; drop only when you have measured the destination and bandwidth budget.

Picking a converter when you're not sure which format wins

A quick decision framework: photos without transparency go to JPG for universal compatibility, WebP for modern sites, or AVIF when bandwidth matters more than the long compatibility tail. UI, logos, and screenshots with flat colors or text belong in PNG or lossless WebP. Animations should be WebP rather than GIF in almost every case. iPhone HEIC files need to be converted to JPG or PNG before anything leaves the Apple ecosystem.

Verify the result at the size it will actually be displayed, not at 100% in an image viewer. Spot-check in the destination — CMS preview, email client, Slack thread — before shipping. And keep the source file whenever the output is lossy; you can always re-export later, but you can't recover detail a compression pass threw away.

When to keep the source format

  • Masters: RAW, TIFF, or PSD until the final export.
  • Vectors: SVG in-app; rasterize only at system boundaries.
  • HEIC with Live Photo or depth: keep HEIC if those payloads matter — JPG flattens to one frame.

Image conversion questions, answered

What is the best image format for the web?

Use AVIF or WebP with JPG fallbacks in a picture element for photos. Use PNG or lossless WebP for UI, screenshots, and transparency. Use SVG for vector UI until a channel forces raster. Match the format to the content class, not a single "best" codec for every case.

Does converting images lose quality?

Lossy formats (JPEG, lossy WebP, lossy AVIF) discard data every time you re-encode. Lossless formats (PNG, lossless WebP) preserve pixels but may cost file size. Always keep a master file when the output is lossy.

What does the quality slider do?

For JPEG, WebP, and AVIF it controls lossy compression strength — higher numbers preserve more detail and larger files. For PNG it maps to DEFLATE compression level: same pixels, different file size.

Should I convert HEIC before uploading?

Usually yes outside Apple ecosystems. Many uploaders and Windows setups still choke on HEIC. Export JPG for sharing or PNG for lossless editing intermediates.

How do I keep transparency when converting?

Use PNG, WebP, or AVIF — not JPEG. If you must deliver JPG, flatten against the real background color first so halos do not show.