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

How do I add a picture-in-picture overlay to a video without uploading it?

Open AnyTool's Video Picture-in-Picture, drop in a main video and an overlay clip (like a webcam or reaction), pick a corner or center position, set the overlay size and edge margins, and choose how to handle audio. It composites the two videos with a self-hosted ffmpeg scale+overlay pass right in your browser, with a live preview before you encode. Nothing is uploaded, the engine core is bundled (no CDN), and there is no watermark or size cap.

  • Overlay a second video on a main video (two inputs)
  • Corner presets (TL/TR/BL/BR) + center, size %, edge margins
  • Audio-mix selector: keep main, keep overlay, mix both, or mute
  • Live preview before encode — self-hosted engine, no CDN, no upload

What is

Picture-in-picture (PiP)

Picture-in-picture overlays a smaller second video on top of a main video — commonly a webcam or reaction clip in a corner. It is built by scaling the overlay and compositing it over the base with an overlay filter, with control over position, size and which audio track is kept or mixed. Client-side PiP runs the encoder in the browser, so neither video is uploaded.

Video Tools

Related terms

overlaywebcamreaction videocompositeffmpeg

How to Add a Picture-in-Picture Overlay

Overlay a second video on a main video in your browser.

40 secWeb browser
  1. 1

    Add both videos

    Drop in the main video and the overlay clip — they stay on your device.

  2. 2

    Position the overlay

    Pick a corner or center, set the size % and margins, and choose an audio option.

  3. 3

    Export

    Preview, encode and download the combined MP4 — nothing is uploaded.

Result: A video with a picture-in-picture overlay

Frequently Asked Questions

No — both clips are composited entirely in your browser with a self-hosted engine.

The files never leave your device and there is no size cap, signup or watermark.

In any corner (top-left, top-right, bottom-left, bottom-right) or centered, with adjustable size and edge margins.

A live preview shows the exact placement before you encode the final file.

You choose: keep the main audio, keep the overlay audio, mix both together, or mute.

That makes it easy to keep narration from the webcam clip while showing the main gameplay or screen recording.

Detailed Explanation

Methodology

How the Picture-in-Picture Tool Works

AnyTool composites a picture-in-picture overlay in the browser with a self-hosted single-threaded ffmpeg.wasm engine — the core (ffmpeg-core.js + the 32 MB wasm) is bundled from npm and served same-origin, so nothing is fetched from a CDN. A live CSS preview lets you place the overlay before any encode runs. On export, an ffmpeg filter_complex scales the second input (the overlay) to a chosen percentage of the main video, snaps both to even dimensions, and overlays it at the selected corner with configurable margins; the result is encoded H.264 + AAC and read back as an MP4 blob. Audio is mapped per the selected mode — keep the main track, the overlay track, mix both with amix, or mute. 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 — neither video is ever uploaded
  • Self-hosted ffmpeg core (bundled) — no CDN
  • filter_complex: scale overlay to % of main, overlay at chosen corner with margins
  • Even-dimension snap; H.264 + AAC encode
  • Audio modes: main / overlay / amix / mute
  • Live CSS preview before encoding; single-threaded (keeps ads working)
Privacy & Security

Privacy vs Upload-based Editors

Most online picture-in-picture editors upload both clips to a server and cap the free tier or add a watermark. AnyTool composites locally with a bundled engine, so the videos never leave your browser, there is no size limit, no watermark and no signup, and it works offline after the first load.

Picture-in-picture: AnyTool vs typical tools
CapabilityAnyToolTypical tools
Data handlingIn your browserOften uploaded
Engine sourceSelf-hosted (no CDN)CDN / server
Overlay controlSize %, corner, marginsVaries
Audio mappingMain / overlay / mix / muteOften fixed
Watermark / capNoneCommon
CostFree, no signupFree/limited

AnyTool is a privacy-first client-side PiP editor — compositing runs locally and nothing is uploaded.