Compress PDF to 500 KB
Bring a PDF under 500 KB without uploading it anywhere. The tool searches for the highest image quality that still fits.
Before you use this: This tool rasterises your PDF — text becomes part of an image and stops being selectable or searchable. That is the trade-off required to hit a hard size target. If you need live text, scan at a lower resolution instead.
Rendering pages and searching for the best quality that fits…
- Original
- —
- Compressed
- —
- Reduction
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- Pages
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How to use this tool
- Choose your PDF or drag it onto the box above.
- The target is already set to 500.0 KB. If your file is already under that, it is returned untouched rather than needlessly rasterised.
- Each page is rendered and re-encoded, then the quality is searched until the whole document fits. Our reference (3 pages) finished at 486.7 KB.
- Download the result. Remember the trade-off stated above: hitting an exact size means the text is no longer selectable.
A widely used limit for résumés and certificates on application portals.
Compress PDF to 500 KB — the specification
| Target file size | Under 500 KB |
|---|---|
| Method | Pages rendered and re-encoded as JPEG |
| Text | Becomes part of the image — no longer selectable |
| Page limit | 60 pages |
| Maximum input | 100 MB |
Compress PDF to 500 KB: why uploads get rejected
Landing under 500 KB is necessary but not sufficient. These are the reasons a file that meets the size still gets sent back:
- The PDF is password-protected. Remove the password first — we cannot and will not bypass encryption.
- The document is already well optimised, so rasterising makes it larger rather than smaller. The tool tells you when this happens.
- The document is text-heavy and the target is very small, so the text becomes unreadable. Check the output before submitting it.
- The PDF has more than 60 pages, which would exhaust your browser tab’s memory.
How it works
Each page is rendered with pdf.js and re-encoded as a JPEG, then the pages are reassembled into a new PDF with pdf-lib. A binary search over image quality — and, if needed, render resolution — lands the result under your target.
The trade-off, stated plainly: this rasterises the document. Text becomes part of an image, so it is no longer selectable, searchable, or readable by automated systems. That is how most "compress to X KB" services work, and it is the only way to hit a hard size target in a browser — but it is a real cost. If you need the text to stay live, use a smaller scan resolution instead of compressing afterwards.
A measured run of this exact preset
Not an estimate. This page’s own code, run against two documented reference PDFs.
| Input | Result | Change | Outcome |
|---|---|---|---|
| a 3-page scanned document 2.92 MB | 486.7 KB | 84% smaller | Under the 500 KB limit |
| a 4-page text document 10.8 KB | 10.8 KB | unchanged | Already under 500 KB — nothing to do |
What the numbers show
The scanned document went from 2.92 MB to 486.7 KB across 3 pages. Almost all of that saving came from re-encoding the page images, because on a scan the images are the document.
The text document is the instructive one. It started at 10.8 KB — already far under the 500.0 KB target — because text is stored as characters and positions, which costs almost nothing. If your PDF is mostly text and still enormous, the size is coming from embedded images or un-subset fonts, not from the words.
And the trade-off that does not show in a table: reaching a hard size target means rasterising the pages, so the text stops being selectable. That is true of every browser-based tool that hits an exact number, and this page says so rather than leaving you to discover it after you have filed the document.
Who needs Compress PDF to 500 KB
Upload portals, email attachments and application systems that enforce a hard per-file limit — where the document is rejected outright rather than being compressed for you.
Compress PDF to 500 KB — frequently asked questions
Does this keep my text selectable?
No. Hitting a hard size target from a browser requires rasterising the pages, which turns text into part of an image. If you need the text to stay live, use the merge, split or rotate tools — those are lossless — or rescan at a lower resolution.
What if it cannot reach 500 KB?
The tool lowers the render resolution and searches again. If it still cannot get there, it reports the smallest size it actually achieved rather than returning something over the limit.
Will the text still be readable?
At moderate targets, yes. At very small targets on a text-heavy document, possibly not — always open the result and check before you submit it.
Can I compress a password-protected PDF?
No. Remove the password in your PDF reader first. We do not offer any means of bypassing PDF encryption.
How do I reduce PDF file size to 500KB without losing text?
You cannot, if you compress it here — reaching a hard size target requires rasterising the pages, which turns text into part of an image. To keep the text live, re-export the source document with lower image quality, or rescan at 200–300 dpi in greyscale. Those preserve the text layer and often get you under 500KB on their own.
Why is my PDF so large in the first place?
Text takes almost no space — a twenty-page text-only PDF is usually under 300 KB. Size nearly always comes from scanned pages, images embedded at print resolution, or fonts that were not subset. Identifying which one applies tells you whether to compress or simply re-export.
Is 500 KB the right target, and what you actually get
Where this limit comes from: Supporting documents on university and visa applications.
The measured run started from a 2.92 MB file of 3 pages and finished at 487 KB, 84% smaller. How far a PDF moves depends almost entirely on what is inside it: a text document is already near its floor and will barely shrink, while a scan is mostly image data and has a great deal to give.
The same source file put through this target and the ones either side of it, measured rather than estimated:
| Target | Result | Reduction | Outcome |
|---|---|---|---|
| 300 KB | 286 KB | 90% smaller | Under the 300 KB limit |
| 500 KB (this page) | 487 KB | 84% smaller | Under the 500 KB limit |
| 1 MB | 970 KB | 68% smaller | Under the 1.00 MB limit |
If the portal gives a range rather than a hard number, take the largest it allows. Every step down this ladder costs detail that cannot be recovered afterwards.
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Your PDF never leaves this device. Contracts, statements and applications are processed entirely in the browser — open the Network tab while you use the page and you will see no upload (how that works).
Disclaimer. Upload limits differ between portals and are often lower than the published figure once the whole application is counted. Check the limit shown on the upload screen itself. Full disclaimer.