Reduce file sizes by up to 95% entirely in your browser — no upload, free, private, works offline.
Compress & convert MP4, MOV, WebM, AVI and more. Trim, crop, resize.
Compress & convert JPG, PNG, WebP and more. Crop, resize, strip metadata.
Compress & convert MP3, WAV, FLAC, AAC and more. Trim and adjust settings.
TL;DR
Localsquash is a free, open web app that compresses and converts video (MP4, MOV, MKV, WebM), image (JPEG, PNG, WebP), and audio (MP3, WAV, FLAC, AAC) files locally in your browser using FFmpeg WebAssembly. No files are uploaded. Typical file size reduction is 50–95%. Works offline after the initial page load. No account, no watermark, no file size cap.
Localsquash is the only compression tool that processes files 100% locally in your browser. No uploads, no servers, no file size limits, and no sign-up.
Files never leave your device. All processing happens locally in your browser.
Instant browser-based compression powered by FFmpeg WebAssembly. No upload delays.
No fees, subscriptions, or watermarks. Unlimited uses with no sign-up required.
Handle files up to 2 GB. No server-imposed caps—limited only by your device’s available memory.
Compress any file in three steps—no sign-up, no upload, no account needed.
Select video, image, or audio compressor from the navigation.
Drop your file locally, then adjust quality and format settings.
One click — your compressed file downloads automatically.
Powered by FFmpeg — supports 100+ media formats.
| Media Type | Supported Input Formats | Output Format | Typical Reduction |
|---|---|---|---|
| Video | MP4, MOV, WebM, AVI, MKV, WMV, FLV | MP4 (H.264) | 70–95% |
| Image | JPEG, PNG, WebP, BMP, GIF | WebP, JPEG, or PNG | 50–90% |
| Audio | MP3, WAV, FLAC, AAC, OGG, Opus, M4A | AAC, MP3, or Opus | 60–90% |
Built for creators, developers, and teams who need smaller files for email, chat apps, social media, and web publishing.
Reduce video size for common email attachment limits in Gmail, Outlook, and other mail clients.
Shrink clips for Discord uploads with higher CRF, lower resolution, and trimming.
Make videos smaller before sending so uploads finish faster and platform recompression is less aggressive.
Compress images for faster loading. Improve Core Web Vitals and SEO.
Optimize photos for Instagram, Facebook. Maintain quality, reduce size.
Reduce podcast file sizes. Perfect bitrate for voice recordings.
Practical walkthroughs for private video compression, browser-based conversions.
HandBrake is the go-to desktop video compressor, but it requires downloading and installing software. Localsquash runs FFmpeg H.264 encoding directly in your browser — no install, no upload, no account needed.
Read guideNeed to make a video smaller, but do not want to upload it to an online converter? Localsquash compresses MP4, MOV, WebM, AVI, and MKV files locally in your browser so your video stays on your device.
Read guideQuick answers about privacy, file limits, supported formats, and how browser-based compression works.
Localsquash uses FFmpeg.wasm, a WebAssembly port of the industry-standard FFmpeg multimedia framework, to perform professional-grade compression directly in your browser with zero server-side processing. FFmpeg is widely used across streaming, editing, and transcoding workflows, which makes it a solid foundation for reliable local media processing.
Video compression uses H.264/AVC encoding with configurable CRF (Constant Rate Factor). CRF 18–23 gives near-lossless quality; CRF 28–35 maximizes compression. Compressed video exports as MP4 for broad compatibility, while trim-only exports keep the original container when possible.
Image compression supports WebP (30–50% better compression than JPEG), JPEG, and PNG with quality adjustable from 1–100%.
Audio compression offers AAC, MP3, and Opus with bitrates from 32kbps to 320kbps.