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

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, watermark or size cap. 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 size cap, signup or watermark.

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, no size cap
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 size cap or watermark and no signup, 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.