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Compress PDF Files Securely

Reduce PDF file size online for free directly in your browser. No upload, no signup, no watermark — your file never leaves your device. Optimize for email and web.

Click to upload or drag and drop

Only PDF files are supported. All processing happens in your browser.

Privacy Guaranteed—No Server Uploads

Performance Note: All processing happens locally in your browser to maintain 100% privacy.

Compress PDF Files Securely

Large PDFs are a pain — they bounce out of email attachments, lag on mobile, and chew up cloud storage quotas. PDFGami's compressor reduces PDF file size by optimizing internal object streams and image data, all without uploading your document. Useful for getting a PDF under a 25 MB email limit, shrinking scanned documents, or trimming an image-heavy report before publishing it on the web.

Privacy Guaranteed

Compression happens locally via pdf-lib. Your documents are never uploaded to a server.

Smart Compression

Optimizes file size while maintaining readability. Image-heavy PDFs typically shrink 40–70%.

No Registration

Compress your files immediately, for free, no account, no watermark on the output.

No Size Limit

Browser-based processing means no server upload cap — compress files of any size your device can handle.

!How It Works, Step by Step

1

Drop the large PDF file into the compressor.

2

The local engine analyzes object streams and image data.

3

Compression runs in your browser — no upload, no waiting in a queue.

4

Review the new file size and download your compressed PDF.

In Your Browser vs. on a Server

FeatureLocal (Us)Cloud Tool
PrivacyAbsolute (no upload)Files stored on vendor servers
File size limitUnlimited (device memory)Often 25–50 MB on free tier
WatermarkNeverCommon on free PDF compressors
SpeedInstant (no upload wait)Upload + queue + download

Technical FAQ

How much smaller will my PDF get when I compress it?
It depends on the original file. PDFs that are mostly text typically shrink 5–20%. PDFs with embedded images or scans typically shrink 40–70% because image streams have the most room for optimization. A 50 MB image-heavy report often comes down to 10–20 MB after compression.
Will compressing my PDF reduce image quality?
Mildly. Our compressor optimizes image streams using PDF's internal encoding, which produces a small visible difference on photo-heavy documents but is fine for screen viewing and standard printing. For print-shop output, keep the original PDF and compress only the copy you send by email.
Is it safe to compress confidential PDFs online?
On PDFGami, yes — the file is parsed and compressed in your browser, never uploaded. For most other "free PDF compressors," the file is uploaded to their servers; that is not appropriate for contracts, medical records, or financial documents.
Can I compress scanned PDFs?
Yes. Scanned PDFs are usually image-heavy and respond well to compression. Note that compression does not OCR the scan — the text remains an image. If you need searchable text, run OCR separately first.
Why is my compressed PDF still big?
PDFs that are already optimized (e.g. produced by modern Word/Pages exports, or already compressed once) have little headroom. Also, PDFs that contain primarily vector graphics or already-compressed JPEGs at high quality settings cannot shrink much further without visible quality loss.
How do I compress a PDF to a specific size, like under 5 MB for an email?
PDFGami compresses to a balanced default. For very strict size targets (e.g. under 2 MB), reduce image quality at the source: re-export the original document with downsampled images, or split the PDF into smaller files using our PDF splitter and email them separately.

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