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Compress anything.

Images, video, audio & PDFs — compressed, never uploaded.

No uploads — 100% local No ads Free & open source

Drop any files here

or browse your files

Files never leave your device. Everything runs in your browser, nothing touches a server — tools you've used even work offline.

Private by design

Your files never leave your device.

Compress Pro is a free, open-source set of compression tools that run entirely in your browser — no uploads, no ads, no accounts. Compress images, PDFs, video and audio, convert between formats, build ZIP archives, and strip photo metadata with the lossless EXIF remover that shows what your photos reveal. Everything happens right on your own device: there is no upload step, so there is no server to trust — and no upload wait, so even a huge video starts compressing the moment you drop it.

No cookies, no analytics, no tracking — the server only ships this page’s static files. Don’t take our word for it: compress a file, switch your connection off, and compress another — it still works, because nothing ever left. Open source — read the code on GitHub.

Before / after

Same photo. 87% fewer bytes.

The same detail after compression to JPG at quality 75 — visually near-identical Detail crop of the original 11-megapixel photo: an alpine meadow below the Langkofel peaks in hazy morning light, at 100% zoom
Original — 8.2 MB
Compressed — 1.1 MB

Original

8.2 MB

Compressed

1.1 MB

Saved

−87%

Real result, not a mock-up: this 11-megapixel photo (4000 × 2666) went through the Compress JPG tool — MozJPEG at quality 75 — and dropped from 8.2 MB to 1.1 MB. What you're dragging is a 100% detail crop of both files, so any compression artifacts would be visible at full size; the byte counts refer to the complete files. Drop the same photo in yourself and you'll get the same number.

Photo via Magnific .

Popular tools

Archives & metadata

How it works

  1. Drop files anywhere on the page, click to browse, or paste with ⌘V.
  2. Pick a quality or preset — or set an exact target size and let the tool find it.
  3. Compress, compare before/after, and download — individually or as a ZIP.

What makes this different

Most online compressors are upload services: your file travels to their server, waits in a queue between banner ads, and comes back smaller. Compress Pro skips the trip — the compression engine runs inside your browser, on your own device. Every difference below follows from that one design choice.

Typical online compressorCompress Pro
Your filesUploaded to a serverNever leave your device
AdsBanners around every stepNone
Price & limitsDaily caps, premium tiersFree, no limits
Source codeClosedOpen on GitHub
OfflineNeeds a connectionWorks offline after first use

The engines under the hood

The same battle-tested open-source encoders professional tools are built on — compiled to WebAssembly, running on your device. Video drives WebCodecs, the hardware encoder already built into your browser, so even long videos convert at full speed.

CategoryEngines running in your browser
JPGMozJPEG — Mozilla’s tuned JPEG encoder
PNGOxiPNG (lossless) and libimagequant, the pngquant engine (lossy)
WebP / AVIFlibwebp and libavif with libaom — the reference encoders
HEIC / GIFlibheif with libde265 for decoding; gifsicle for GIF
VideoWebCodecs (your browser’s hardware H.264/HEVC/VP9 encoder), orchestrated by mediabunny
AudioLAME (MP3), FFmpeg’s AAC encoder, libFLAC (FLAC), plus WebCodecs for Opus
PDFGhostscript for compression; pdf-lib and pdf.js for merge, split and rendering
SVGSVGO — the standard SVG optimizer
FontsHarfBuzz for subsetting; Google’s woff2 with Brotli for WOFF2
Archives7-Zip 24.09 compiled to WebAssembly, with fflate for ZIP/gzip fast paths

Frequently asked questions

Are my files uploaded anywhere?

No — everything runs right in your browser, and the server only delivers this page. Files never leave your device; close the tab and everything is gone.

Is it really free?

Yes — completely. No ads, no accounts, no watermarks, no daily limits, no premium tier. Everything runs on your own device, so there are no server costs to pass on — and the app is open source.

How do I know my files aren’t uploaded?

Two ways. Test it: compress a file, switch your connection off, and compress another — everything keeps working, because there was never anything to send. And check it: the app is open source, so anyone can read the code on GitHub and verify that no upload exists.

Is there a file size limit?

No hard limit — processing is bounded by your device’s memory, not by an upload cap. Multi-hundred-megabyte videos and PDFs work; they just take longer on slower hardware.

What can I compress or convert?

Images (JPG, PNG, WebP, GIF, HEIC, AVIF, SVG), PDFs, MP4/WebM/MOV video and MP3/WAV/M4A/FLAC/OGG/OPUS audio — plus ZIP archives, converters between formats like HEIC to JPG or MOV to MP4, and a lossless EXIF remover for photo metadata.

Will compression make my files look worse?

Only as much as you allow. Every tool has a quality control and a before/after compare, and target-size mode finds the best quality under a limit like 2 MB. Lossless modes (PNG, SVG, EXIF removal) don’t touch pixels at all.