AnyTool
Your files never leave your device. All processing happens locally in your browser.

Green Screen (Chroma Key)

Green-screen chroma key removal — replace the background with a solid color or your own image — in your browser, no upload, no watermark

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How do I remove a green screen from a video without uploading it?

Open AnyTool's Chroma Key, drop in a green-screen clip, pick the key color (green, blue or a custom color) and tune the similarity (tolerance) and edge-blend, then composite the subject onto a new background — a solid color or an uploaded image. It runs with a self-hosted ffmpeg engine in your browser — the video is never uploaded, the engine is bundled (no CDN), and there is no signup or watermark (files up to 500 MB). Note: it composites onto a background rather than exporting transparent video.

  • Key out green, blue or a custom color with tolerance + edge-blend
  • Composite onto a solid color or an uploaded background image
  • Composites onto a background (not transparent-video output)
  • Self-hosted engine — no CDN, no upload, no watermark

What is

Chroma key

Chroma keying (green-screen removal) makes a chosen color in a video transparent so the subject can be placed over a different background. A similarity/tolerance setting controls how much of the color range is keyed, and edge-blend softens the cutout edges; the keyed subject is then composited onto a new background. This tool composites onto a solid color or an uploaded image (it does not export transparent video). Client-side keying runs in the browser, so the video is never uploaded.

Video Tools

Related terms

green screencompositingtoleranceedge blendffmpeg

How to Remove a Green Screen

Key out a color and composite onto a new background in your browser.

45 secWeb browser
  1. 1

    Add a video

    Drop in a green-screen clip — it stays on your device.

  2. 2

    Key the color

    Pick green, blue or a custom color and tune tolerance and edge-blend.

  3. 3

    Export

    Choose a solid color or image background, composite and download an MP4 — nothing is uploaded.

Result: A video composited onto a new background

Frequently Asked Questions

Yes — choose green, blue or a custom color, then adjust the similarity (tolerance) and edge-blend.

Tolerance widens or narrows the keyed color range, while edge-blend softens the cutout edges.

No — it composites the subject onto a new background (a solid color or an uploaded image) rather than exporting transparent video.

The output is an MP4 with your chosen background already composited behind the subject.

No — the keying and compositing run entirely in your browser with a self-hosted engine.

The video never leaves your device and there is no signup or watermark (files up to 500 MB).

Detailed Explanation

Methodology

How the Chroma Key (Green Screen) Tool Works

AnyTool removes a green (or any chosen) screen entirely in the browser using a self-hosted single-threaded ffmpeg.wasm engine — the core (ffmpeg-core.js + the 32 MB wasm) is bundled from npm and served as a same-origin asset, so nothing is fetched from a CDN. The clip is written to ffmpeg's virtual filesystem (MEMFS) and the chromakey filter keys out the chosen color using adjustable similarity and blend, producing a foreground with the screen removed. That foreground is then overlaid onto a background — either a solid color source or an uploaded image scaled to the frame — and flattened to yuv420p for a clean H.264 MP4 read back as a blob. Note: the self-hosted core encodes VP8 only and cannot output alpha, so the tool composites the foreground onto a background rather than exporting transparency. Single-threaded is deliberate: the multi-threaded core needs SharedArrayBuffer + cross-origin isolation (COOP/COEP), which would block cross-origin ad iframes.

  • Runs client-side — the video is never uploaded
  • Self-hosted ffmpeg core (bundled) — no CDN
  • chromakey filter keys the chosen color (similarity/blend)
  • Foreground overlaid on a color source or uploaded image
  • Flattened to yuv420p H.264 MP4
  • Composites onto a background (VP8 core can't encode alpha)
  • No backend, no signup, files up to 500 MB
Privacy & Security

Privacy vs Upload-based Green-screen Tools

Most online green-screen tools upload your footage to a server and cap the free tier or add a watermark. AnyTool keys and composites locally with a bundled engine, so the video never leaves your browser, there is no watermark and no signup (files up to 500 MB), and it works offline after the first load.

Chroma key: AnyTool vs typical tools
CapabilityAnyToolTypical tools
Data handlingIn your browserOften uploaded
Keyingchromakey (similarity/blend)Varies
BackgroundColor or uploaded imageLimited
Outputyuv420p H.264 MP4Varies
CostFree, no signupFree/limited

AnyTool is a privacy-first client-side green-screen tool — keying runs locally and nothing is uploaded.