Converts MP4 files to WebM format — universal video playback on any device to web-optimized video. All conversion happens locally in your browser with no file size limits.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Grade videos with 18 filters across Color, Artistic, Blur, and Lighting (grayscale, sepia, pixelate, gaussian blur, vignette, brightness/contrast/saturation) plus a live still-frame preview. Export MP4, WebM, or GIF — local FFmpeg work, unlimited saves.
Convert WebM videos to Apple-friendly MOV for Final Cut and QuickTime workflows. Bring web clips into Mac editing — local FFmpeg work, unlimited saves.
Smooth shaky handheld footage with motion-compensated stabilization. Salvage walking tour videos without gimbals — local FFmpeg work, unlimited saves.
Convert MP3 to AAC for better quality per bit on Apple devices and streaming. Modernize libraries for smaller sizes — local FFmpeg work, unlimited saves.
Shrink MP3 files by lowering bitrate with quality presets — fit podcasts into feed limits. Cut a 50 MB episode to 15 MB cleanly — local FFmpeg work, unlimited saves.
MP4 (MPEG-4 Part 14) uses lossy compressed encoding and is best for universal video playback on any device — phones, smart TVs, web browsers, and social media. WebM (WebM Video) uses lossy compressed encoding and excels at web-optimized video — streaming, embedded players, and HTML5 video tags with fast loading. Converting between them lets you take advantage of each format's strengths — for example, using a compressed format for sharing and a lossless format for editing. All conversion happens locally in your browser with no file size limits.
Typically 30–50% smaller than H.264 MP4 at equal quality — a 100 MB homepage video lands near 60 MB. Multiply across a media library for real bandwidth wins.
All modern browsers play WebM; Safari joined fully in recent versions. Serve WebM primary with MP4 fallback for certainty.
CRF 30–33 for web embeds balances size and looks. Talking heads compress further than action footage.
No — conversion runs locally in your browser with FFmpeg. Only saves touch the network — downloads are unlimited.
Video to MP3 Converter
Extracts the audio track from uploaded video files (MP4, MOV, AVI, WebM) and encodes it as a high-quality MP3 file. Free to start with no signup.
Crop Video
Crop the visual area of your MP4 or WebM video directly in the browser with 9:16, 1:1, 16:9 presets or custom dimensions with X/Y offsets. Free to start with no signup.
Video Compressor
Reduces MP4, MOV, and WebM video file sizes with a configurable CRF 20–40 slider (default 28, libx264 fast preset), plus a GIF mode with color-palette control. Videos never leave your device — compression runs locally in your browser with FFmpeg WASM.
Video to GIF
Convert MP4/WebM to GIF animations. Videos up to 250MB. Videos never leave your device — compression and conversion run locally in your browser with FFmpeg WASM.
Subtitle Translator
Translate pasted SRT or VTT subtitle text into 9 languages (Spanish, French, German, Japanese, Chinese, Hindi, Portuguese, Russian, Arabic) while preserving every timestamp — AI-powered with your own API key, text never stored.
Video Watermark Adder
Burn text watermarks into a video with 5 position presets (bottom-right default, fixed 24px white on semi-transparent black box). Brand one clip at a time — local FFmpeg work, unlimited saves.