Compress PDF Online
Reduce your PDF file size by re-encoding images and stripping metadata — free, private, and entirely in your browser.
Drag & drop PDF files here
or click to browse
Max 50MB per file · 100MB total
How it works
Upload your PDF
Drag and drop or click to select the PDF you want to compress. Up to 75 MB supported.
Choose a compression level
Pick Light for minimal quality loss, Medium for a balanced result, or Strong for maximum size reduction.
Download the compressed PDF
See the before/after size comparison and download your smaller PDF — all processed in your browser.
About this tool
PDFs grow large primarily because of the images they contain — scanned pages, embedded photographs, product screenshots, and diagrams are stored at their full captured resolution. For many use cases — emailing a colleague, uploading to a portal with a 10 MB limit, archiving thousands of invoices — that resolution is far beyond what anyone needs. ToolkitFlow's PDF Compressor targets exactly those image streams: it re-encodes embedded JPEG images at a lower quality setting and optionally scales down their resolution, then strips document metadata that adds weight without adding content.
Three compression levels let you control the quality-versus-size tradeoff. Light re-encodes at 90% JPEG quality with no resolution change — visually indistinguishable on screen and monitors. Medium targets 75% quality and scales images above 150 DPI, which is right for most office documents and scanned reports. Strong compresses to 60% quality and caps image resolution at 100 DPI, best when the file must fit a strict size envelope and screen readability is acceptable. Text, vector graphics, and fonts are never touched — the PDF remains fully searchable and copyable at every level.
Common Use Cases
- ›Fitting a scanned 25 MB annual report within a 10 MB email attachment limit
- ›Reducing cloud storage usage when archiving years of PDF invoices or statements
- ›Compressing product catalogs and brochures before publishing them on a website
- ›Shrinking large presentation PDFs so they share quickly via messaging apps
- ›Preparing high-resolution scan archives for long-term storage without ballooning disk usage
Privacy & Security
All PDF processing runs directly in your browser using WebAssembly and pdf-lib. Your files are never uploaded to any server — everything is processed locally on your device, so your documents remain completely private even without an internet connection.
Frequently Asked Questions
How much will my PDF shrink?
It depends almost entirely on the images inside the file. Scan-heavy and photo-rich PDFs commonly shrink 40–70% on Medium or Strong. PDFs composed mainly of text and vector graphics will see 5–20% reductions regardless of level, because those elements are unaffected by image re-encoding.
What is the difference between Light, Medium, and Strong compression?
Light re-encodes images at 90% JPEG quality with no DPI scaling — changes are imperceptible at normal reading zoom. Medium uses 75% quality and downscales images above 150 DPI, which is invisible on screen but results in meaningfully smaller files. Strong uses 60% quality and caps images at 100 DPI — visibly softer at high zoom but much smaller, ideal when a file must fit within a strict size limit.
Will the text in my PDF still be searchable after compression?
Yes. The compressor only modifies embedded image streams. Text, fonts, hyperlinks, form fields, and document structure are completely untouched — the PDF remains fully searchable and selectable after compression.
Why did my PDF barely shrink even on Strong compression?
The most common reason is that your PDF contains mainly text, vector graphics, or already-compressed images. If embedded JPEGs were already encoded at low quality by the originating software, further re-encoding yields diminishing returns. The same applies to PDFs previously compressed by another tool.
Is my original file modified?
No. The tool reads your file into browser memory, produces a new compressed copy, and offers that copy for download. Your original file on disk is never written to or altered.