alphaPDF · Free PDF tool
Compress PDFs locally in Chrome.
Prepare a PDF for email, a submission portal or everyday sharing without uploading its contents to a compression website. alphaPDF Free includes a Compress PDF tool with choices that balance file size and document fidelity. The right setting depends on how the recipient will use the document.
How to reduce PDF file size
- Install alphaPDF and add the document you want to compress.
- Open Compress PDF and choose the source PDF.
- Choose lossless optimisation to preserve quality, or a smaller raster result when a more substantial size reduction matters.
- Run compression, compare the output size and inspect text, images and document features before downloading it.
Choose quality according to the job
Lossless optimisation is the conservative starting point when you want to preserve the document. Some PDFs are already well optimised, so a large reduction is not guaranteed. A smaller raster result converts pages to images and may reduce fine detail. Check small print, diagrams and scanned handwriting at a useful zoom level.
Know what image-based output changes
Raster compression can discard searchable text, vector artwork, links and interactive forms. If those features matter, use lossless optimisation or keep the original. Pro OCR can add a searchable text layer to an image-based result, but it does not restore original form fields, vector graphics or links.
No upload, and no guaranteed percentage
Compression runs locally in Chrome and is included in Free. The result depends on the source document and settings. A scan with large page images behaves differently from a compact text PDF. Keep the original so you can try another setting if the first output does not suit your needs.
Frequently asked questions
Is PDF compression free in alphaPDF?
Yes. Compress PDF is part of alphaPDF Free. OCR and Word conversion require Pro.
Will every PDF become much smaller?
No. Already compressed documents may show little reduction. Check both the output size and its quality rather than relying on a promised percentage.
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