PhotoRoom vs ReSmush.it

PhotoRoom's API takes a product or portrait photo and returns a background-removed, background-generated, or otherwise edited image via a single multipart POST, authenticated with an x-api-key header per its docs at docs.photoroom.com — a separate GitBook site from the marketing homepage. A live CORS preflight against its segmentation endpoint reflected two different arbitrary Origin headers back with credentials enabled, so browser-side calls are supported directly. New accounts get a 1,000-image sandbox allowance for testing plus limited free production calls to the Remove Background endpoint, with paid plans covering higher volume and the full Image Editing API.

ReSmush.it is a free, keyless image-optimization API — best known as the backend behind the ReSmush.it WordPress plugin — that accepts a source image URL and returns a JSON payload with the compressed image's URL plus original size, compressed size, and percent reduction. A live call against api.resmush.it needed no credentials and returned Access-Control-Allow-Origin: *, so it works directly from browser JavaScript. The plain http:// endpoint immediately redirects to https, so the service is https-only despite requiring no API key.