A TinyPNG alternative that runs on your Mac (offline)

TinyPNG is a fantastic free service — until you stop and notice that the file you’re about to compress is a screenshot of an unreleased product, a customer’s onboarding flow, or a private design comp. Now you’re uploading proprietary work to a third party’s servers to save half a megabyte. Here’s how to get the same compression locally on Mac.

Why this happens

TinyPNG, ImageOptim’s “scout the cloud” mode, Compressor.io and similar services upload your file, run pngquant/MozJPEG/equivalent on their servers, then send the result back. The compression is genuinely good — what they’re really selling is the convenience of not installing anything. The tradeoff: your image leaves your machine.

The native way (free, offline, slow)

Install the same tools TinyPNG uses, under the hood:

brew install pngquant jpegoptim

Then for PNG:

pngquant —quality=65-80 —strip input.png

And for JPEG:

jpegoptim —max=80 —strip-all input.jpg

--strip and --strip-all remove EXIF, which TinyPNG does by default. The output is functionally indistinguishable from what TinyPNG would return. The catch is you’re in Terminal, you have to remember the flags, and there’s no batch progress bar.

The faster way (paid, offline, fast)

Download Melt — a $9.99 Mac app that wraps the same pngquant + MozJPEG-style pipeline in a drag-and-drop interface. Nothing leaves your computer.

1. Download Melt and open it.
2. Drag your image (or whole folder) in.
3. Pick output format and quality. 80 is the equivalent of TinyPNG's default.
4. Click Compress. EXIF strips automatically.

The math: TinyPNG free tier is 20 images per month, then $25/year for the dashboard. Melt is $9.99 once for unlimited everything, and it works on a plane.

How much smaller will it really get?

For PNG screenshots: 70-85% smaller — same as TinyPNG. For JPEG photos at quality 80: 50-70% smaller — same as TinyPNG. The compression algorithms are essentially equivalent because they’re the same open-source codecs.

Why it matters

For a personal blog photo, TinyPNG is fine. For client work, NDA’d designs, internal product screenshots, or anything you wouldn’t paste into a public Slack channel — running compression locally is genuinely the right call. The “never leaves my Mac” property is the whole point.

Honestly, even setting aside the privacy thing, batch compressing 200 files through a web uploader is its own kind of slow. Local tools are just faster for anything past a single image.