Your image files optimized in one click.
100% private, serverless, yet completely free! 100% offline, zero uploads!
Every operation—compressing, resizing, cropping, converting formats, rotating, and filters—happens locally inside your browser. Your images never leave your computer.
Optimize & Edit Images
Select or drag image files to begin editing in your secure local sandbox.
Click the plus icon or drag files here to start (PNG, JPG, WEBP, HEIC, GIF)
What you can accomplish
Explore all the client-side power tools packed directly into your browser sandbox.
Smart Compression
Reduce image size by up to 90% while preserving visual clarity. Works locally on JPEG, WEBP, and PNG formats.
Exact Pixel Resizing
Adjust width and height dimensions with a responsive aspect ratio lock. Perfect for digital banners or profile icons.
Visual Crop & Transform
Cut out parts of an image with drag handles, rotate in 90-degree steps, or flip axes non-destructively in seconds.
Universal HEIC Converter
Drop iPhone HEIC files to automatically convert them to web-ready JPEG, PNG, WEBP, or compile multiple items into a PDF.
100% Offline Privacy
No bandwidth or network usage. Images process inside your local sandbox. Safe for personal documents, ID cards, and screenshots.
Precise Crop & Rotation
Visual grid guides. Rotate, skew, horizontal/vertical flip, and select custom aspect ratios (16:9, 4:3, 1:1) instantly.
Bulk Parallel Processing
Load multiple images of different formats, tweak optimization configurations collectively, and download all as a ZIP file.
Frequently Asked Questions
Everything you need to know about MellowImage's privacy, compression techniques, and browser processing.
MellowImage uses standard browser APIs (`HTMLCanvasElement`, `FileReader`, and `WebCodecs`). When you load an image, it is rendered onto an offscreen memory canvas. The canvas is compiled back to JPEG or WEBP formats with a quality scale value (0.0 to 1.0) using the canvas encoding engines. This performs high-speed compression entirely in your browser sandbox.
Yes, fully. Standard browsers do not render Apple's HEIC photos directly. MellowImage integrates the client-side `heic2any` library, which converts HEIC images into browser-compatible JPEGs in memory immediately after upload, allowing iPhone users to compress and edit their files directly.
You can disconnect your network connection (Wi-Fi, Mobile Data, or Ethernet) and load this application. You will find that all tools—image rendering, canvas cropping, compression, comparison slider, filters, and ZIP creation—continue to execute perfectly. Click the "Privacy Sandbox Test" link in the footer to verify this test.
No limitations. Since processing runs inside your browser environment, boundaries are only set by your system memory (RAM) and CPU. No account creation, subscription paywalls, or daily upload limits are applied.
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