No. All processing happens 100% locally in your browser using the HTML5 Canvas API and MediaRecorder API. Your video never leaves your device. This ensures complete privacy and security — no data is ever transmitted to any external server.

The tool supports most common video formats including MP4, WebM, MOV, AVI, and MKV. However, browser compatibility varies — Chrome and Edge generally support the widest range. For best results, use MP4 (H.264) or WebM files. Safari users may experience limited format support.

Output is primarily in WebM format (VP8 or VP9 codec), which is natively supported by the browser's MediaRecorder API. MP4 output may be available in some browsers (notably Safari and newer Chrome versions). VP9 offers better quality at smaller file sizes compared to VP8.

The tool processes video in real-time by playing through the source video while simultaneously recording the resized output. This means a 2-minute video takes approximately 2 minutes to process. This approach ensures smooth frame capture and audio synchronization without requiring massive memory buffers.

• Scale to Fit: The entire video is scaled to fit within the output dimensions. Letterboxing (black bars) may be added to preserve aspect ratio.
• Scale to Fill: The video is scaled to completely fill the output dimensions. Excess portions are cropped automatically from the edges.
• Stretch: The video is stretched to exactly match the output dimensions, potentially distorting the aspect ratio.
• Custom Crop: You manually select the crop area by dragging the frame on the video preview. Only the selected region is kept and scaled to the output size.

Google Chrome and Microsoft Edge provide the best experience with full feature support. Firefox works well but may have larger output file sizes. Safari supports basic functionality but MP4 output and some advanced features may be limited. For optimal results, use an up-to-date Chromium-based browser.

Common use cases include: resizing videos for social media platforms (Instagram, TikTok, YouTube Shorts), converting horizontal videos to vertical format for mobile viewing, creating Open Graph video previews (1200×630), reducing file size for email attachments, and adapting videos for website embeds with specific dimension requirements.

Yes, the tool preserves the original audio track whenever possible. It uses the Web Audio API to capture audio from the source video and muxes it with the processed video stream. In some older browsers, audio preservation may not be supported, in which case the output will be video-only.