Powerful Client-Side Tools
Select a utility to process files instantly without any upload.
Video Looper
Loop any video N times or for a set duration. Export as MP4.
Video to GIF
Convert any video clip to an animated GIF. Control FPS, resolution, and duration.
Video Compressor
Reduce video file size using H.264 encoding. Choose quality level.
Video Trimmer
Cut a video to a precise start and end point using a visual timeline. No re-encoding.
Extract Audio
Pull the audio track from any video file. Export as MP3 or WAV.
Audio Converter
Convert between MP3, WAV, OGG, AAC, and FLAC formats in browser.
Audio Trimmer
Trim audio to a start and end timestamp. Download the clipped result.
Image Converter
Convert PNG, JPG, WebP, AVIF between formats. Batch up to 10 files.
Image Compressor
Compress JPG/PNG/WebP with quality slider. See before/after file size.
PDF to Images
Convert each PDF page to a JPG or PNG image. ZIP downloaded automatically.
Video Merger
Combine multiple videos into one. Trim each clip, set the sequence, and export as MP4.
Audio Merger
Join multiple audio clips into one track. Trim each clip and arrange the sequence.
Images to PDF
Combine multiple images into one PDF. Drag to reorder before merging.
Why ZenTools?
Local processing is not just a feature. It is a paradigm shift in privacy and speed.
Privacy by architecture
There is no server. Every operation runs inside your browser tab using WebAssembly. Your files never leave your device - close the tab and everything is gone.
Instant results
No queues, no waiting rooms, no watermarks. Drop a file, adjust one setting, click Process. Your result is ready in seconds.
Powered by open source
Built on FFmpeg.wasm, PDF.js, jsPDF, and the HTML5 Canvas API - the same battle-tested libraries powering professional tools worldwide.
How local processing works
Your web browser is a powerful runtime environment. Rather than uploading your files to a remote server, ZenTools uses WebAssembly compilation of FFmpeg, PDF.js, and browser APIs to run code directly inside your CPU and RAM.
When you drop a file, it is loaded into the browser tab's sandbox memory. Once you hit process, the compilation executes, and the browser prompts a standard file download. Your file never crosses a network.
Drop your file
Select or drag your media into the dropzone.
Adjust settings
Tailor bitrate, presets, or pages in your tab.
Save locally
Process instantly and save directly to disk.
From the blog
Guides for working with video, audio, images, and PDFs
Introducing ZenTools: 100% Private, Browser-Native File Utilities
How to Loop a Video Online
Best Free Video Looping Tools in 2026