Chroma Key Tool — free, in your browser

Chroma key is the technique of shooting a subject against a single solid color — usually green or blue — then replacing that color with something else (or making it transparent). Our tool does the "make it transparent" half: it builds a cut-out you can drop onto any background.

Diagram: shoot on a solid color, the color goes transparent, then drop the subject on any background — Shoot on a solid color, turn that color transparent, then place the subject on any background.

How to chroma key

Open your file. Drop a chroma-key image or video above, or click browse. The preview updates as soon as it loads.
Pick the key color and threshold. Keep the green or blue preset, then raise or lower Similarity threshold until the backdrop vanishes but your subject stays sharp. Edge shrink eats the colored fringe; Edge smoothing softens the matte.
Export. Images save as a transparent PNG. Video saves as a transparent WebM or a PNG-sequence zip.

Diagram: chroma key isolates the key color, builds a matte, removes the color, composites onto a new background — Chroma key: isolate the key color, build a matte, remove the color, composite onto a new background.

Diagram: the four controls — key color, similarity threshold, edge shrink, edge smoothing — and what each does — The four knobs: key color (green or blue), similarity threshold, edge shrink (eats the fringe), edge smoothing (softens the matte).

Image or video?

Still image? You get a transparent PNG. Video? You get a transparent WebM or a PNG-sequence zip. Both are processed on your device — nothing is uploaded.

Diagram: image exports as transparent PNG, video as transparent WebM or PNG sequence, both on-device — Image becomes a transparent PNG; video becomes a transparent WebM or PNG-sequence zip — neither is uploaded.

Tips for a clean edge

If a colored halo remains, nudge Edge shrink up by 1–2 px.
If hair or fine detail gets chewed away, lower Edge shrink and raise Edge smoothing.
You can click the preview to sample any color as the key — handy for uneven or lit backdrops.

Diagram: colored halo fix is raise edge shrink; chewed hair fix is lower shrink and raise smoothing — Colored halo left? raise Edge shrink. Fine hair chewed away? lower shrink and raise Edge smoothing.

Common questions

What is chroma key?

It's the process of swapping a uniform backdrop color for another image or for transparency. Filmmakers and streamers use it to place a subject in front of any scene. This tool handles the transparency step so your subject exports as a clean cut-out.

Are my files uploaded?

No. Everything runs in your browser; we never receive your media.

What if the edge still has a colored tint?

Our tool builds the transparency mask but does not desaturate semi-transparent pixels, so a very faint tint can linger on soft edges. Raising Edge shrink is the quickest fix.