Under a size, or to a spec
Name the ceiling instead of guessing at a quality slider.
Quality sliders ask the wrong question. You do not want quality 63, you want a file under 8MB. This works backwards from the limit: it encodes, measures, adjusts and repeats until it finds the best-looking file that still fits, then shows you every attempt.
How it searches
- Encodes at high quality and measures the real byte count.
- Binary-searches the quality until it is just under your ceiling.
- If quality alone cannot get there, it steps the resolution down and searches again.
- Stops at the largest, best-looking version that fits.
Common limits
- Discord free upload: 10MB, or 500MB with Nitro.
- Gmail and most mail servers: 25MB per message, attachments included.
- Outlook: 20MB, which is lower than Gmail and catches people out.
- WhatsApp sticker: 100KB at exactly 512 by 512 pixels.
- Slack free plan: 1GB per file, but 5MB is the practical courtesy limit.
- Most job application forms: 2MB, often without saying so until you fail.
- Passport and visa photo uploads: frequently 240KB or less.
Why a file is bigger than you expect
- A photograph saved as PNG is several times larger than the same photo as JPG, because lossless compression cannot do much with photographic detail.
- Phone cameras now shoot 12 megapixels or more, which is far more than any screen shows.
- Screen recordings at 60 frames a second are twice the size of the same thing at 30.
- Video bitrate, not length, is usually what makes a clip too large to send.
Questions
How do I get a file under a specific size?
Give the tool the limit rather than a quality number. It encodes repeatedly and keeps the best result that stays under the size you named.
Will it reduce resolution?
Only if it has to. Quality is lowered first, because that is less visible. Resolution drops only when no quality setting can reach the target.
Does it work for video?
Yes. Video is encoded to a calculated bitrate for its duration, then checked against the limit the same way.