Exactly under 50 KB, automatically
Upload portals do not negotiate: if the field says 50 KB, a file at 51 KB is rejected. Instead of guessing quality settings, this page runs a binary search — it re-encodes your photo as a JPG, checks the size, adjusts the quality and repeats until the file lands just under 50 KB at the best quality that fits. If a photo genuinely cannot fit (very large dimensions), it says so plainly and the resize control is right there on the page.
Everything happens in your browser — the photos, signatures and documents people compress for application forms are exactly the files that should never be uploaded to a random server. Need a different target? Every size from 10 KB to 200 KB has its own page, and the full compressor lets you type any number.