Type the limit in KB. Each photo gets the highest quality whose finished JPG fits under it, found by encoding the real file — not guessed from a formula — and the row tells you the exact size it landed on.
How the size is found
For each file, the converter encodes the full picture at quality 10. If that already fits, it searches upwards — binary search, seven or so real encodes — for the highest quality whose finished file is still at or under your limit. The metadata and colour profile are attached before each measurement, so the number you see is the size of the file you download.
If quality 10 is still too large, quality is not the problem: the pixel count is. The row says so and offers a smaller size. With Shrink the pixels on, the converter reduces the pixel size step by step until the file fits, and the row prints the size it started from and the one it ended at.
Step by step
- Drop one JPG or many. Other formats — HEIC, PNG, WebP — work too; they are converted and sized in one step.
- In Quality, Target is already selected: enter the limit in KB, or pick 20, 50, 100, 200 or 500.
- Add a minimum if the form has one, and decide whether the pixels may shrink when quality alone cannot reach the limit.
- Press Download. Each card shows the exact size, the quality the search chose, and whether the limit was met.
Minimums are real too
Upload portals often reject files that are too small as well as too large — 20 to 50 KB is a typical range. Set At least in the Quality panel and any file that comes out under it even at the highest quality is flagged on its row rather than padded with junk bytes. For portals with a pixel box and DPI as well, the form presets set all three at once.