Are my files uploaded to a server?

No. The compression runs entirely inside your browser using your own device’s processing power. The file never leaves your computer or phone, which is why it also works when your connection drops.

Why is the result a little under 50 KB instead of exactly 50 KB?

The limit is a ceiling, not a goal. The tool returns the highest-quality version that stays under your number, which usually lands just below it.

My PDF cannot reach 50 KB — what now?

When even the lowest quality cannot get under the number, the tool says so and shows the best size it reached — nothing is delivered as if it had fit. Delete the pages you do not need before compressing, or switch the same tool to Split: it then cuts the document into parts that each stay under the limit. Scanned pages full of photographs need far more data than text pages.

Will the text still be selectable?

No. To hit an exact size the pages are re-rendered as images, so the result is a visual PDF. Keep the original if you need to copy text later.

Compress a PDF to 50 KB

Runs on your device · Your file never leaves your device.

This page opens with the limit already set to 50 KB. Check the limit printed next to your form’s upload field, then drop your PDF and download a copy that fits.

The compressor searches for the best quality that still comes in under 50 KB rather than crushing the file to the smallest size possible, so the result stays as legible as the limit allows. The worked example below shows, measured, what 50 KB did to a sample three-page scan.

Everything happens on your own device. The PDF is never uploaded, which is why the tool also works with the internet switched off, and why a passport scan or a contract can go through it without a second thought.

Worked example: a measured run of this tool

We ran a 3-page scanned letter in English and Arabic (fictional) (539.3 KB) through this page in a browser, the way a visitor would, and checked what came out. The figures below were measured on the result, not estimated.

Settings: The page’s preset: 50 KB, Compress mode. Nothing else was changed. The tool counts 1 KB as 1,000 bytes. The limit is a ceiling: when the tool’s best quality already fits well under it, that is the file you get.
File size: 539.3 KB → 44.9 KB (≤ 50.0 KB)
Pages: 3 → 3
Opens as a valid file: ✓
English words present in the English lines (any order): 100 % (71 / 71) → 98.6 % (70 / 71)
English text as written, in reading order: 99.8 % → 99.5 %
Numbers, totals and dates on their own line, English: 5 / 5 → 4 / 5 · ⁨1 March 2021⁩ → ⁨1 March 202]⁩ — check failed
Arabic words present in the Arabic lines (any order): 95.2 % (60 / 63) → 85.7 % (54 / 63) — check failed
Arabic text as written, in reading order: 97.3 % → 92.6 %
Numbers, totals and dates on their own line, Arabic: 5 / 5 → 3 / 5 · ⁨١٢ سبتمبر ٢٠٢٦⁩ → ⁨—⁩ · ⁨٠١٠٠٥٥٥٠١٩٩⁩ → ⁨.١٠٠١600-198⁩ — check failed
Time taken in the test browser, button to result: 1.5 s

A detail of the original file at full size — Before: the original, 100 % crop

The same detail of the result at full size — After: the result, same crop

What this example does not show: To reach the size, every page becomes an image, so the text in the result cannot be selected or searched. Text recognition was run on the original and on the result, and the rows above show what it read in each: compression can cost some of the numbers on the Arabic page. The sample is three greyscale scanned pages; more pages or colour photographs need more room, and when a file cannot fit, the tool says so instead of handing over a file that is too big. The same tool’s Split mode then cuts it into parts that each fit.

Measured on 2026-10-04 with the site’s own code (build 5a72bc1). Files: scanned-letter-3-pages.pdf result

How to compress a PDF to 50 KB

Drop the PDF onto the box, or tap it to pick the file from your device.
The target is already 50 KB; change it only if your form allows more.
Press Compress. The pages are re-rendered while the tool searches for the best quality that fits.
Download the finished PDF, or the ZIP of parts if one file could not reach the limit.

Supported formats and limits

Input: PDF (any version)
Output: PDF under 50 KB
Target: 50 KB by default; any KB or MB value
Where it runs: In your browser; the file is never uploaded
File size: Limited by your device memory, not by a server quota

Not for: Keeping selectable text — compression rasterises pages to hit an exact size, so the result is a visual PDF.

Frequently asked questions

Are my files uploaded to a server?: No. The compression runs entirely inside your browser using your own device’s processing power. The file never leaves your computer or phone, which is why it also works when your connection drops.
Why is the result a little under 50 KB instead of exactly 50 KB?: The limit is a ceiling, not a goal. The tool returns the highest-quality version that stays under your number, which usually lands just below it.
My PDF cannot reach 50 KB — what now?: When even the lowest quality cannot get under the number, the tool says so and shows the best size it reached — nothing is delivered as if it had fit. Delete the pages you do not need before compressing, or switch the same tool to Split: it then cuts the document into parts that each stay under the limit. Scanned pages full of photographs need far more data than text pages.
Will the text still be selectable?: No. To hit an exact size the pages are re-rendered as images, so the result is a visual PDF. Keep the original if you need to copy text later.

Compress a PDF to 50 KB

Worked example: a measured run of this tool

How to compress a PDF to 50 KB

Supported formats and limits

Frequently asked questions

Other sizes and destinations

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