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Lock PDF

Add a password to an unlocked PDF and download a protected copy in your browser.Free, fast, and secure

Add a password to any PDF with this free lock PDF tool. Choose a strong password, protect your file, and download the encrypted copy in seconds — processing runs entirely in your browser with no uploads to third-party servers.

Password-protecting PDFs is essential when sharing contracts, financial statements, medical records, or client deliverables. A locked PDF prevents casual opening and adds a basic layer of access control before you email or store sensitive documents.

To remove protection from a file you own, use our PDF Password Remover instead. Compresso also offers offline bulk image and video compression for Mac and Windows when you need to reduce large media folders without uploading files to the cloud.

Try Other Free Tools

JPG to PNG Converter

Convert JPG images to PNG format with transparency support.

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PNG to JPG Converter

Convert PNG images to JPG format for smaller file sizes.

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WebP to PNG Converter

Convert modern WebP images to widely supported PNG format.

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PNG to WebP Converter

Optimize your PNGs by converting them to the WebP format.

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WebP to JPG Converter

Convert WebP images to standard JPG format easily.

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JPG to WebP Converter

Improve web performance by converting JPGs to WebP.

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SVG to PNG Converter

Rasterize vector SVG files into high-quality PNG images.

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Compress JPG

Reduce the file size of your JPG images without losing quality.

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Compress PNG

Shrink PNG files while maintaining perfect transparency.

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Compress WebP

Make your WebP images even smaller for faster loading.

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Compress SVG

Minify SVG code and reduce vector file sizes.

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Batch Image Resizer

Resize multiple images at once to custom dimensions.

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Image Cropper

Crop images to specific aspect ratios or custom sizes.

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Image Flip/Rotate

Quickly mirror or rotate your images to any angle.

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Image Watermarker

Add text or logo watermarks to protect your images.

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Image Metadata Remover

Strip Exif and other metadata for privacy.

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Image Background Remover

Automatically remove image backgrounds with AI.

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PDF to JPG Converter

Convert each page of a PDF document into high-quality JPGs.

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JPG to PDF Converter

Combine multiple JPG images into a single PDF file.

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Compress PDF

Shrink PDF file sizes for easier sharing and storage.

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Merge PDF

Combine multiple PDF files into one document.

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Split PDF

Extract specific pages or split a PDF into separate files.

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PDF to Markdown

Convert PDF content into editable Markdown text.

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Markdown to PDF

Generate professional PDF documents from Markdown.

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Unlock PDF

Remove security and passwords from PDF documents.

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Lock PDF

Encrypt your PDF files with a secure password.

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PDF Page Rotator

Fix misaligned pages by rotating them in your PDF.

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SVG Pattern Generator

Create beautiful repeatable SVG patterns for backgrounds.

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Favicon Generator

Generate all favicon sizes from a single image.

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App Icon Generator

Create iOS and Android app icons in all required sizes.

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Social Media Resizer

Perfectly size images for Instagram, Twitter, and more.

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Placeholder Generator

Generate custom placeholder images for web development.

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QR Code Generator

Create custom QR codes for URLs, text, or Wi-Fi.

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Barcode Generator

Generate standard barcodes for products and assets.

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Image to Base64

Encode your images into Base64 strings for CSS/HTML.

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Base64 to Image

Decode Base64 strings back into viewable image files.

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Extract Images from PDF

Save all images found within a PDF document.

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Color Palette Generator

Extract a beautiful color palette from any image.

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Image Color Picker

Identify specific colors in your images with a hex picker.

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Image Resolution Checker

Check the DPI and pixel dimensions of your images.

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Exif Metadata Viewer

View detailed camera settings and GPS info of images.

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Image Resolution Upscaler

Increase image resolution using AI upscaling technology.

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Grayscale Converter

Turn any color image into a classic black and white photo.

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Invert Image Colors

Create a negative effect by inverting image colors.

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Blur Image Generator

Apply customizable blur effects to your images.

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Image Shadow Generator

Add realistic drop shadows to your images.

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Image Border Adder

Add stylish borders and frames to your pictures.

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View All 48 Tools

Need to compress images or videos?

Download the app and compress up to 200 images and videos at once with no file size limits. Get access to advanced compression and batch processing features.

Download for Mac

Free to download • 100% offline