Does compression upload my images?

No. Compression runs in your browser in a Web Worker. Your images never leave your device — there is no server and no account.

The compressor targets your chosen maximum size while preserving as much quality as possible. For most photos at typical web sizes the difference is invisible; very aggressive targets on detailed images can introduce visible artefacts.

Which formats are supported?

JPG, PNG and WebP. The output keeps the original format, so a JPG stays a JPG and a PNG stays a PNG.

How do I compress an image to a specific KB or MB size?

Set the "Target max size" field to your limit (for example 0.2 for ~200 KB or 1 for ~1 MB). The tool re-encodes and downscales until the result is at or below that size, then shows the actual saving.

What does the "max width/height" setting do?

It caps the longest side of the image in pixels (default 1920). If a photo is larger it is downscaled to fit, which is usually the biggest single saving — a 4000px phone photo rarely needs more than 1920px for web use.

Why is my compressed PNG not much smaller?

PNG is lossless, so it compresses far less than JPG or WebP — especially for photographs. If you need a much smaller file and don't need transparency, convert the PNG to JPG or WebP instead.

Is there a file size or batch limit?

No fixed limit beyond your device's memory. Because everything runs locally, very large images or large batches are bounded only by available RAM in your browser tab.

Image Compressor — Gera Tools

Compress JPG, PNG and WebP images privately

Large images slow down websites, blow past email attachment limits, and fill up storage. This tool reduces image file size while keeping photos looking sharp — useful for web pages, email, CMS uploads with size caps, and freeing up space. It’s for anyone who needs a smaller file without an upload-and-wait round trip.

How it works

The tool loads the browser-image-compression library and runs it in a background Web Worker, so the page stays responsive. For each file it calls imageCompression(file, { maxSizeMB, maxWidthOrHeight, useWebWorker: true }). The library first downscales the image so its longest side fits your pixel cap, then iteratively re-encodes at decreasing quality until the result is at or below your target size. The original format is preserved, and each result shows the before/after size and percentage saved.

Example

A 4.2 MB, 4032×3024 phone photo for a blog post: set Target max size to 1 MB and Max width/height to 1920. The tool downscales to 1920×1440 and re-encodes, producing roughly a 0.8 MB JPG — about a −81% saving — with no visible loss at blog display size.

Use case	Target size	Max dimension
Email attachment	1–2 MB	2048 px
Website hero / blog	0.2–0.5 MB	1920 px
Thumbnail / avatar	0.05–0.1 MB	512 px

Compression happens locally, so it’s fast and your images are never sent to a server.