Compress multiple videos with one shared CRF setting (18 high quality, 23 default, 28 smaller, 35 maximum) encoded libx264 medium preset with 128k AAC audio. Studios batch 20 daily uploads at CRF 28 — local FFmpeg WASM, 2 free batches a day.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Compress multiple MP4 videos at once for email, web, or messaging. YouTube studios batch-optimize daily uploads with consistent CRF settings. Everything runs locally in your browser — nothing is uploaded.
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.
Burn one shared SRT subtitle file permanently into a whole batch of videos with font-size and bottom/top/middle position control. Course creators hard-sub 20 lessons for platforms that ignore caption files — FFmpeg WASM, 2 free batches a day.
Convert and compress images to AVIF via canvas encoding with 4 presets — Web 1920px/q60, Balanced 2048px/q75 (default), High Quality 3000px/q85, Maximum original-size/q95 — plus free quality (10–100) and max-width (0–4000, 0 = Original) sliders that decouple the preset. Only wider images downscale; single saves as optimized.avif, batches as *.avif in avif-images.zip — local work, 2 free batches a day.
Shrink image batches to JPEG or PNG (no WebP output) at full source dimensions with one quality slider (10–100, default 80). Store owners compress 300 product shots before upload — local processing, 2 free batches a day.
CRF 23 for balanced quality, 28 for web uploads (roughly half the size), 18 for archival masters. A 20-video batch of 100 MB uploads at CRF 28 lands near 35–45 MB each with YouTube-acceptable quality.
FFmpeg WASM runs sequentially on your CPU: a 100 MB 1080p file takes 1–3 minutes on a laptop. A 10-video batch runs 15–30 minutes — keep the tab open and download each finished file or the final ZIP.
Every file outputs MP4 H.264 (medium preset) at its original resolution with 128k AAC audio — playable on every phone, TV, and browser. Keep 4K masters archived; compress 1080p proxies for sharing and upload. Files over 100 MB trigger a memory warning — close other tabs before running.
No — compression runs locally in your browser with FFmpeg WASM; footage never leaves your device. Only the final saves count against Pro downloads (signed-in free: 2 a day).
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.
Bulk MP4 Compressor
Compress multiple MP4 videos at once for email, web, or messaging. YouTube studios batch-optimize daily uploads with consistent CRF settings. Everything runs locally in your browser — nothing is uploaded.
Bulk Video Size Reducer
Hit exact file-size targets (10/25/50/100 MB, default 50) across video batches for email and messaging caps. Teams fit 15 clips under Gmail's 25 MB wall — local FFmpeg WASM, 2 free batches a day.