Compress PDF to Exact KB
Direct answer: give KBExact the exact size your portal demands — a maximum, or a minimum–maximum window — and it fits your PDF to that number in your browser. It re-encodes the images inside the PDF first, so your text stays selectable whenever the target allows; it never uploads your file.
🔒 Processed 100% in your browser. Certificates, ID proofs and mark sheets never leave your device.
Processing… your file never leaves this device.
Ceiling, window, or preset
Ceiling mode is for portals that set only a maximum ("PDF must be under 200 KB"). Window mode is for portals that set both a minimum and a maximum — yes, files are rejected for being too small too. Preset mode loads a verified portal specification from our preset library, each with its official source and the date we checked it.
Working with scans of certificates? A scanned PDF is mostly one big image per page; the tool handles that, and if the pages must be rebuilt as images to reach a small target, it tells you before you download. For photos and signatures, use the photo & signature resizer instead — that is a window-plus-dimensions job. Need a quick fixed number instead? Try compress PDF to 200 KB, to 100 KB, to 500 KB or to 1 MB.
How the fitting works
The engine first rebuilds the PDF without its metadata, then re-encodes each embedded photo at a searched quality — binary search, not a slider guess. If that cannot reach the target, it reduces image resolution in measured steps. Only as a last resort does it rasterise pages, always with the disclosure shown in the report. Read the full story on our method page.
Questions
How is this different from other PDF compressors?
Most compressors offer vague levels (low / medium / high) and leave you guessing whether the result fits your portal. KBExact works backwards from the number your portal demands: you give the ceiling or the window, and the tool searches for the best quality that lands inside it — and tells you honestly if it cannot.
Will my text stay selectable?
Usually, yes. KBExact first re-encodes only the images inside the PDF and leaves text and vectors untouched. Only if that cannot reach the target does it rebuild pages as images, and before you download it says so plainly: text is no longer selectable in that copy.
Is my PDF uploaded?
No. The compression runs entirely in your browser with code downloaded once as part of this page. You can verify it: open your browser developer tools, watch the Network tab while compressing — there are no uploads.
Why aim 5% under the limit?
Because portals disagree on what a kilobyte is: 1 KB is 1,024 bytes in one counting and 1,000 in another. A file exactly at the limit in one system is over it in the other. The 5% margin beats the 1-KB-over rejection. You can turn the margin off.
What if the target cannot be reached?
You get an honest failure message instead of a silently oversized file. Try a higher target, or split the document if your portal allows multiple uploads.