Hi Product Hunt! I'm Yasuo, a solo developer from Japan. I built Gashuku out of frustration with my own workflow. Every time I wrote a blog post, I'd drag images into TinyPNG, hit the 5MB limit, switch to Squoosh, manually dial in the same settings I always use — quality 0.8, WebP, max 1280px — then repeat for every image. Mindless repetition. Two things were missing from every tool I tried: 1. A generous file size limit. AI-generated images can easily reach 6–8MB. Gashuku supports up to 20MB per file — 4× the limit of TinyPNG. 2. Presets. If I use the same settings 90% of the time, I should be able to save them and recall in one click. The "no server uploads" part came from client work. Uploading a client's website screenshots to a third-party server always felt off. With Gashuku, your images never leave your browser — compression runs entirely in JavaScript. It's completely free, no account required. I'm also planning to add new features going forward — would love to hear what you'd find most useful. I'd love to hear how you use it — or what's missing. Happy to answer any questions!

Gashuku

Compress images privately in your browser.no server uploads.

Compress images privately in your browser.no server uploads.