Shrink PDF size by re-rendering pages at a controlled resolution and quality.
Compression rasterises pages, so text becomes an image. Use a lower scale for scans, higher for text-heavy documents.
Drag & drop files here
or use the button below · processed locally on your device
Output settings
Free file tool
Free PDF Compressor online
Shrink PDF size by re-rendering pages at a controlled resolution and quality. Use the tool directly in your browser with no sign-up. It supports multiple source files in the same session, so it also works as a free batch tool when you have more than one file.
Free to use
No payment required for this tool.
Batch conversion
Queue multiple source files in one session.
Browser-based
The conversion workflow runs from the web page on your device.
No sign-up
Start the file workflow without creating an account.
What PDF Compressor is useful for
✓Meeting PDF upload-size limits
✓Reducing attachment size
✓Creating a smaller sharing copy of a large document
Input and output checks
Accepted input: pdf.
✓Open the downloaded output before deleting or replacing the source file.
✓Check the details that matter for your use: page count, dimensions, orientation, text, duration or metadata.
✓For batch jobs, confirm every queued file produced the expected output.
✓If quality or size matters, compare more than one settings combination before choosing the final copy.
How to use this calculator: PDF Compressor
1Upload one or more PDF files.
2Choose the render scale and JPEG quality.
3Start PDF compression and let each page be re-rendered at the selected settings.
4Review the resulting file size and output quality.
5Download the compressed PDF.
Worked conversion example
Example: upload a 12 MB source file, choose a moderate quality setting, and run the tool. Exact output size depends on image detail, fonts, pages, duration and codec efficiency; compare the downloaded result visually before replacing the original.
Accepted input
pdf
Batch behaviour
Multiple files supported
Output settings
Setting
Example/default
Effect
Render scale
1.4
Changes how the output is encoded or arranged; preview the result before relying on it.
JPEG quality
65
Changes how the output is encoded or arranged; preview the result before relying on it.
How the browser process works
Shrink PDF size by re-rendering pages at a controlled resolution and quality. The page sends the selected file and settings to its pdf-compress browser engine, creates a new output and downloads it without overwriting the source.
Compression rasterises pages, so text becomes an image. Use a lower scale for scans, higher for text-heavy documents.
Privacy, quality checks and limitations
Keep the original file until the downloaded output has been opened and checked.
Verify page count, orientation, dimensions, text legibility, audio/video duration and metadata relevant to your use.
Browser-local processing reduces routine upload exposure, but your device, browser extensions and download location still matter.
A converted preview is not proof of legal authenticity, archival compliance, accessibility or digital-signature validity.
Reduce PDF file size by controlling page render scale and JPEG quality. This is useful when a PDF is too large to upload, email, store, or share easily.
How PDF compression works
The current compressor re-renders PDF pages as images and encodes them with the selected quality. Lower scale and quality can produce smaller files but can also reduce visual detail.
Important PDF compression trade-off
Higher scale / quality
Better visual detail, usually larger file size
Lower scale / quality
Smaller output, potentially lower visual quality
Text layer
The current compressor rasterises pages, so text becomes part of the page image
Related PDF Tools
Continue with a related PDF task using another OneCalcApp tool.
