Why 100KB is the number portals keep asking for
Fill out an exam application in India — SSC, IBPS, a state PSC, a university admission form — and sooner or later you meet the same red error line: "Document must be less than 100KB." Your phone's scanner app just produced a crisp 4MB PDF of your certificate, and the portal refuses anything over a hundred kilobytes. That gap is exactly what this page closes: upload the file, and it comes back guaranteed under 100KB, ready for the portal's upload button.
Generic compressors make this harder than it should be. They offer vague "high / medium / low" presets and leave you guessing whether the result fits — so you compress, check the size, get rejected, compress again. This tool removes the loop: the target is fixed at 100KB, the engine measures the rebuilt file, and you only get a download when the file is genuinely at or under the limit. No second-guessing, no rejected uploads at 2 AM before a deadline.
Everything runs in your browser. Nothing is uploaded, nothing is stored, and there is no account — which matters when the document is your caste certificate, marks card, or ID proof. The tool is free and the output carries no watermark.
How to compress a PDF to exactly 100KB
- Tap "Select PDF" (or drop the file into the box below it). The file opens instantly in your browser — scans, exported documents, merged files, anything.
- Hit "Compress to 100 KB". The target is pre-set; there is nothing to configure. The tool renders each page and binary-searches the highest image quality that keeps the total under 100KB.
- Watch the per-page progress. You'll see "Processing page 3/12…" as it works through the document. Large scans take a little longer — keep the tab open.
- Check the result stats. The page shows the before/after sizes and the page count, so you can confirm the file is under 100KB before downloading.
- Download and upload. The file is named with its target size. Right-click → Properties (or Get Info) to double-confirm, then upload it to your portal.
What actually fits inside 100KB
A hundred kilobytes is a tight budget, so it helps to know what it buys. One to three pages of plain text or clean black-and-white scans compress to 100KB beautifully — text stays sharp and the file often lands well under the limit. These are the classic portal documents: a single certificate, an ID proof, a one-page application form.
Pages with photographs, colored seals, or stamps are heavier. They still reach 100KB, but the images come out softer — readable, not pretty. The practical move: zoom to 200% on any page carrying an official seal, a handwritten signature, or a QR code, and confirm it is still legible before you submit.
Long, photo-heavy documents may not reach 100KB honestly. If a 40-page photo report can't be squeezed under the limit without turning pages to mush, the tool says so and hands you the smallest honest size instead of a ruined file. In that case, split the document into the pages the portal actually needs with the Split PDF tool, then compress the smaller file.
Tips for a 100KB PDF that still looks sharp
- Crop scans to the page edges first. Desk, shadows, and table surface around your scan waste your 100KB budget on pixels nobody needs. A tight crop is the single biggest quality win at small sizes.
- Compress from the best original you have. Re-compressing an already-compressed PDF compounds artifacts. If your scanner app saved a "maximum quality" version, use that as the input.
- Check seals and QR codes at 200% zoom. These degrade first. If a QR code won't scan after compression, the file is too aggressive — but at a fixed 100KB target, the fix is a cleaner source scan, not a bigger budget.
- One document per portal limit. If a form asks for your certificate at 100KB and your photo ID at 100KB, compress them as two separate files rather than merging first — a merged file splits its budget across both documents.
- Don't pre-shrink with another tool. Running the file through a different compressor first usually makes the final result worse, not better. Feed this tool the original.
When 100KB isn't the right target
Not every portal asks for 100KB. Email attachments are comfortable up to 1MB, many university portals accept 500KB, and some exam forms want 200KB. The rule is simple: always compress to the portal's stated number, never smaller "just to be safe." Extra compression only costs you quality for zero benefit — a 100KB file uploaded to a 1MB portal is just a needlessly soft document.
If your portal wants a different size, EzySize has you covered either way: compress a PDF to 200KB for the classic exam-form middle ground, compress a PDF below 500KB for resumes and portfolios, or type any exact number into the main Compress PDF tool. One honest caution about this exact-size page: because it rebuilds pages as images to guarantee the file size, text is not selectable in the output — if you need selectable, searchable text, the main tool is the right choice.