Free online tools that run entirely in your browser.
Free online tools that run entirely in your browser.
Your files never leave your device. Compress images, merge PDFs, convert video to GIF, generate Excel formulas, beautify screenshots, and transcribe audio — no uploads, no accounts, no tracking.
Image CompressorShrink JPG, PNG & WebP photos with no visible quality loss.
- Compress image to 100KB
- JPG vs PNG vs WebP guide PDF ToolsMerge multiple PDFs into one, or shrink oversized files.
- Merge PDF files online
- Why PDFs get so big Video to GIFTurn MP4 and MOV clips into GIFs — no watermark.
- MP4 to GIF converter
- Frame rate & size guide Excel Formula BotDescribe the calculation in plain English; AI writes the formula.
- Formulas it handles well
- Excel vs Google Sheets Screenshot BeautifierBrowser frames, gradients, and shadows for your screenshots.
- Styles for different audiences
- Export tips Audio to TextWhisper AI transcription that runs 100% on your device.
- Choosing a Whisper model tier
- Recording tips for accuracy
- Compress image to 100KB
- Merge PDF files online
- Convert video to GIF
- AI Excel formula generator
- Screenshot beautifier
- Free audio to text transcriber
- Convert HEIC to JPG free
Popular tools
How it works
Every YuliusBox tool runs on your device using modern browser technology — WebAssembly, the Canvas API, and on-device AI models like Whisper. When you drop a file into a tool, it is processed by your own CPU and GPU; nothing is sent to a server, stored in a database, or logged. That means no queues, no file-size quotas imposed by server costs, and no privacy trade-offs — your tools even keep working offline once the page has loaded.
No upload
Files are processed on your device and never sent to a server.
No signup
Every tool works instantly. No accounts, no email walls.
Free
All core tools are free to use, with no watermarks.