Compress PDF to 500 KB
Get a PDF under 500 KB for an upload limit — the tool keeps adjusting until it fits, or tells you it cannot.
Drop a PDF here
or click to browse — target is 500 KB
Files are processed on your device and never uploaded.
How it works
- Drop your PDF onto the tool.
- Click Compress. Each pass re-renders the pages at a lower resolution and measures the result.
- Download when the target is met — or read why it could not be reached.
Frequently asked questions
- How does it hit an exact size?
- By measuring rather than guessing. The first pass renders at 150 dpi and measures the file. Because JPEG size tracks pixel count, and pixel count is proportional to dpi squared, the resolution needed to hit 500 KB can be predicted from that first measurement — so the second pass usually lands, instead of blindly trying eight settings. Up to five passes run, and the smallest result is kept.
- What if it cannot reach 500 KB?
- It says so plainly and gives you the smallest version it managed, rather than silently handing over an oversized file. The usual cause is page count: every page costs a minimum number of bytes once it is an image, so a hundred-page document has a floor that no quality setting can go below. Splitting the file or removing pages is the realistic answer there.
- Will the text still be selectable?
- No. Reaching a specific size in a browser means re-rendering each page as a photograph, so the output contains pictures of text rather than text. You lose selection, search and copy-paste. Always keep your original — and if the text must stay text, removing pages or splitting the document reduces size without that cost.
- Why do upload forms ask for 500 KB anyway?
- Because attachment and upload limits are set per system, not per document — email gateways, court e-filing portals, job application forms, visa and university systems all impose their own caps. The number is arbitrary from your side, which is exactly why a tool that targets a specific figure is more useful than one with vague quality presets.
- Is my document uploaded to a server?
- No. Every pass runs inside your browser and the download is produced on your device. Nothing is transmitted, which also explains why very long documents can be slow — your own hardware is doing the rendering, several times over.
About this tool
Upload limits are unforgiving: a portal that wants 500 KB will reject 700 KB without explanation. This tool works to that number directly — it renders the document, measures the result, and adjusts until the file fits or it runs out of room.
The approach is measure-then-predict rather than trial and error. Rendering a PDF is the expensive step, so probing settings blindly would mean waiting through many full passes. Instead the first pass at 150 dpi produces a real measurement, and since JPEG size scales with pixel count — which is proportional to resolution squared — the resolution required for 500 KB follows from that measurement. Most documents are done in two or three passes.
It is honest about failure, which matters more than it sounds. Every page has a floor cost once it becomes an image, so a long document simply cannot be squeezed below a certain size without becoming unreadable. When that happens the tool says so, reports the smallest size it achieved and the resolution it used, and points you at splitting the file — rather than quietly handing back something still over the limit.
The trade-off is the same one every browser-based PDF compressor makes, stated up front: pages become images, so text stops being selectable and searchable. Keep your original. When the goal is simply getting under a limit and the text matters, removing unneeded pages or splitting the document achieves it without any loss at all. Everything runs locally, so the file is never uploaded.