Flowfiles ← Video Overlay

Overlay a GIF on a Video Without Upload

Everything stays on your device — no server, no account — 100% In-Browser

Most "add a GIF to video" sites work by uploading your file to a server, processing it remotely and sending it back. This tool does the opposite: the video and the GIF never leave your computer. This page explains how local, no-upload overlaying works, why it's better for privacy and speed, and what trade-offs come with doing video work entirely in the browser.

Composite a GIF onto your video without ever uploading it — private, offline-capable, no account, no watermark.

Open the Video Overlay tool →

How no-upload overlaying works

When you drop a file onto the page, the browser creates a local blob URL — a reference to the file in memory on your own machine. The tool loads the video and the GIF from those local references, draws each video frame onto a hidden canvas, draws the GIF's current frame on top, and records the canvas with the browser's built-in MediaRecorder. The finished video is built and saved locally. At no point is a network request made with your media.

Why this matters for privacy

If a file is never uploaded, there is no remote copy to worry about — nothing to be stored on someone else's disk, cached on a CDN, indexed, scanned or exposed in a breach. For personal videos, client footage under NDA, internal recordings or anything unreleased, keeping the whole process on your device removes a category of risk entirely. You can even disconnect from the internet after the page loads and the tool still works.

Speed and file-size freedom

Upload-based tools are gated by your connection and by size caps — large videos take ages to send and often hit a "max file size" wall. With local processing there's no upload step and no artificial cap; the practical limits are your device's memory and the time you're willing to spend on the export. Because encoding is recorded in real time, a one-minute video takes roughly a minute at 1× speed, and the 2× / 4× modes shorten that when you can drop the audio.

The honest trade-offs

Doing everything in-browser means the work uses your CPU rather than a remote server, so very long or very high-resolution clips depend on your hardware. Output formats are limited to what your browser can record — WebM everywhere, MP4 on browsers that support it. In exchange you get privacy, no queue, no sign-up, and no watermark. For adding a GIF to a clip, that's a trade most people happily take.

What you still control

No-upload doesn't mean fewer features. You still get nine anchor positions plus custom placement, size as a percentage, opacity, rotation, full-clip looping or a timed window, base-video trimming, output scaling and bitrate — all running locally with a live preview.

Frequently asked questions

Does it work offline?

Yes, once the page has loaded. The processing is entirely local, so you can disconnect and still overlay and export your video.

Do I need an account?

No. There's no sign-up, no login and no email required. Open the tool and use it.

Is there a file size limit?

No upload cap, because nothing is uploaded. The limit is your device's memory and patience for the real-time render.

Which browsers support it?

Recent Chrome, Edge, Firefox and Safari. The tool warns you if your browser lacks the MediaRecorder support it needs.

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