Introduction
helloIMG is an image optimization service: send it an image and it comes back compressed, converted to a modern format, and — if you ask — resized or smart-cropped. You can use it three ways:
- The API directly —
POSTan image toapi.helloimg.io, get back a smaller one. - The WordPress plugin — LW Image converts every upload to WebP or AVIF automatically, with no code.
- AI image tools — generate alt text and SEO metadata, or remove a background, from the same account.
How it works
You upload an image
An image file plus a JSON data field describing what you want — a
quality level, a target format, a resize — go to the optimize endpoint as
multipart/form-data.
helloIMG processes it in the background
The request returns quickly with a job_id. Processing — compression,
format conversion, resizing — happens asynchronously.
You get back a smaller image
Poll the job until it's completed (or let the request block for you — see
API quickstart), and you get a URL to the
optimized image plus the before/after size and the percentage saved.
Optimization levels
Every optimize request picks a level, either as a boolean flag or as a
single level string:
| Level | What it means |
|---|---|
normal | Default quality — a safe, general-purpose compression. |
aggressive | Higher compression, smaller files, still visually clean. |
ultra | Maximum compression for when file size matters most. |
lossless | No quality loss at all — the file gets smaller, pixels don't change. |
See Optimize API for the exact request shape.