Compress PDF to 300 KB
A free online PDF compressor that gets your file under a 300 KB upload limit. It compresses in steps until the file actually fits the target, entirely in your browser, with nothing uploaded.
This tool compresses a PDF to 300KB online by aiming at the number: pages are re-encoded, the result is measured, and quality steps down until the file is genuinely under 300 KB. No guessing with a fixed-level compressor, and no finding out at upload time that the file is still 340 KB.
300 KB caps show up on exam registration forms, scholarship portals, and document uploads that allow a few pages rather than one: a signed declaration, a two-page certificate, a short marksheet. The compression runs entirely in your browser: your documents are never uploaded to any server, including ours.
How to compress a PDF to 300KB
- Select your PDF
Drag the file into the box above or click to browse. Scans and phone photos saved as PDF work too.
- Keep the 300 KB target selected
The target is preset. Portals with stricter caps can switch to 200 KB or 100 KB; looser ones to 500 KB or 1 MB.
- Click Compress PDF
The tool compresses in passes until the file fits under 300 KB, showing progress as it goes.
- Download the result
The file downloads with its final size shown, so you know it will pass the portal check before you upload.
What fits in 300 KB
300 KB sits between the strict 200 KB caps and the roomier 500 KB ones, and that extra margin matters for multi-page uploads:
- 1–5 pages: fits comfortably with clearly readable text.
- 6–10 pages: usually fits, with softer but legible pages.
- 12+ pages: often below what readability allows; the tool reports the achievable floor honestly.
For documents that will not fit, drop unneeded pages with Remove PDF Pages or split the file with Extract PDF Pages and upload in parts. If the portal actually allows 500 KB, the 500 KB version keeps noticeably more quality; if it insists on 200 KB, the 200 KB version is preset to that.
Scans are the problem, and the fix
A default scanner setting produces 200–300 DPI color pages at 1–3 MB each, several times the whole budget for a document a reviewer reads on screen. Re-encoding each page at screen-appropriate resolution is what makes a 3 MB scanned form land under 300 KB while staying legible.
Two tips that help at the source: scan in grayscale instead of color, which typically halves the starting size, and scan at 150 DPI rather than 300 for documents that only need to be read, not printed.
Why use this converter?
Private by design
Conversion runs in your browser. Your files are never uploaded, stored, or seen by anyone.
Genuinely free
No daily task limits, premium tiers, or watermarks. Local conversion costs nothing to run.
Instant results
No upload and download queues. Files convert in about a second, even on slow connections.
Works everywhere
Windows, Mac, Linux, iPhone, Android: any modern browser, no app or software install.
Frequently asked questions
How do I compress a PDF to 300KB online for free?
Drop the PDF into the tool above, keep "Under 300 KB" selected, and click Compress PDF. Quality steps down automatically until the file fits, then it downloads. Free, no signup, nothing uploaded.
How is this different from a normal PDF compressor?
A normal compressor applies one fixed level and the final size is whatever it happens to be. This tool measures the output and compresses again until the file is actually under 300 KB, or tells you the real minimum if the target is impossible.
How many pages can fit under 300 KB?
Up to about 5 pages compress comfortably with clearly readable text; up to about 10 usually fit with softer quality. Beyond that, consider removing pages or splitting the document.
Is my document safe?
Yes. Everything runs locally in your browser, so certificates, forms, and ID documents never leave your device. No watermark, no signup, no server-side copy.
The tool says my PDF cannot reach 300 KB. Why?
Long or very dense documents have a floor below which pages stop being readable. Rather than deliver an illegible file, the tool reports the smallest readable size. Removing pages or splitting the PDF gets you under the cap.
Can I reduce PDF size to 300KB without losing quality?
Usually, yes. The tool starts from gentle compression and only steps down as far as the 300 KB cap requires, so short documents keep near-original sharpness and longer ones stay clearly readable.