Usually no visible change
A 1 MB budget is enough for a high-quality JPG of most phone photos at full or near-full resolution. Zekoya tries the highest quality first and only lowers it until the file fits.
Big PNG screenshots
Screenshots saved as PNG can be several megabytes. Keep PNG if text must stay pixel-perfect — Zekoya reduces the colour palette to fit — or switch to JPG/WebP for a much smaller file.
Questions
Does it work with HEIC photos from iPhone?
Not yet. Share or export the photo as JPG first (most iPhones do this automatically when uploading to a browser).
What is the largest file I can use?
Up to 50 MB and 100 megapixels per image.