Image Tool
How to use
What it does
A bundle of everyday image operations: compare two pictures side by side or overlaid, stitch several images horizontally or vertically, stamp a watermark, and convert an image into an inline Base64 data string. All processing happens locally in the browser, so images are never uploaded — which matters when you are working with private photos or internal assets. Two merged tabs load on demand: a GIF maker and a pixel-art editor.
How to use it
Drop in or select your images first, then choose a panel at the top. In compare mode drag the divider to spot differences; in stitch mode pick a direction and gap; in watermark mode set the text, position, opacity and font size; Base64 mode shows a string you can paste straight into HTML. Results can be downloaded or copied out.
FAQ
Where are my photos processed - in the browser or on a server?
Entirely in your browser. All 20 sub-tools work on a local <canvas>, files are read with FileReader or object URLs and never uploaded, so editing also works offline once the page is loaded.
What does the invisible watermark actually do?
It hides your text with LSB steganography - the message bits are embedded in the lowest bits of each pixel's RGB channels. Export the result as PNG, then load that PNG into the extract section to read the hidden text back.
Why is my exported Base64 smaller than the original image?
Images larger than the max-size setting are downscaled before encoding (default 800 px, slider goes up to 2000 px), and JPEG quality defaults to 80%. Raise both sliders in the Base64 tab for higher fidelity.
Related articles
More tools
Random anime-ish pictures and sized placeholder images
Convert between JSON, CSV, XML, YAML and Markdown
Focus on work, rest efficiently
QR code and Code128 barcode generator
Deduplicate, diff, reverse and word frequency
Function plots, waveforms, spectra and Fourier series