A draggable before/after comparison slider is a compelling way to show a transformation — a photo edit, a renovation, a design revision — letting viewers directly compare two images by sliding a divider across them.
Upload a before and after image to preview the interactive slider, drag the range control to reveal more or less of each image, then copy the complete HTML, CSS, and small JavaScript snippet needed to implement the same comparison slider in your own project.
The technique layers the "after" image as the base, with the "before" image clipped to a percentage width controlled by a range input, giving a smooth, native-feeling slider without needing an external JavaScript library.
Because everything runs locally in your browser, results appear instantly and nothing you type or upload is ever sent to a server.
Bookmark this page if you expect to use this tool regularly — it loads fast and behaves the same way every time, with no account needed.
This kind of task shows up constantly in everyday writing, coding, design, and admin work, which is exactly why a dedicated, focused tool saves so much back-and-forth.
A tool that does one job well, without a cluttered interface or unrelated features competing for attention, tends to be faster to use than a heavier all-in-one app.
Frequently asked questions
Does this require an external JavaScript library?
No, this uses only a native HTML range input and a small amount of vanilla JavaScript to control the clip width — no external library dependency needed.
Can I use this for comparing anything besides photos, like design mockups?
Yes, the same technique works for comparing any two images side by side, whether that's photos, design mockups, or diagrams.