How to Add CRT Scanlines to a Video for Free

Scanlines are the quiet backbone of the retro look. They add just enough texture to make a clip feel like it's playing on an old tube TV — without turning your footage into noise. Here's what they actually are, when to reach for them, and how to add them to any video in Glitchest for free, right in your browser.

What scanlines and phosphor glow really are

Old CRT monitors drew each frame one horizontal line at a time. Between those lit lines sat thin gaps, and your eye read the whole thing as a soft striped grid. That grid is what we call scanlines: evenly spaced dark horizontal lines laid over the image.

The second half of the effect is phosphor glow — the gentle bloom that CRT phosphors gave to bright areas. Highlights spread slightly and pick up a warm halo. On their own, scanlines can look flat and mechanical. Paired with a touch of glow, they read as genuinely nostalgic instead of like a screen filter.

When to use them

Scanlines are a tool, not a default. They shine in a few specific situations:

• Retro and vaporwave edits — anything aiming for an 80s or 90s broadcast feel.
• Under titles and lower-thirds — a subtle line pattern behind text sells the "old monitor" idea without much effort.
• Lo-fi music loops and moodboards — where a soft, imperfect texture is the whole point.
• Gaming and terminal footage — screen recordings look right at home with a light CRT grid.

If your footage is already busy or high-contrast, go light. Scanlines add visual density, and too much of it buries the actual content.

How to add scanlines in Glitchest

Everything happens in your browser. There's no upload, no account.

1. Open the editor. It loads straight into a workspace — nothing to install.
2. Load your clip. Drop in a video or image. It stays on your device; nothing is sent to a server.
3. Add the scanlines effect. Pick the scanline preset to lay the horizontal grid over your footage. You'll see it applied live in the preview.
4. Layer in phosphor glow. Add a glow pass so highlights bloom the way a real tube would. This is the step that turns a flat overlay into a convincing screen.
5. Tune the opacity and spacing. Lower the scanline opacity until the effect reads as texture, not as bars. If your tool has a line-density control, wider spacing feels vintage while tight spacing feels more like a modern panel.
6. Export MP4. Hit export and Glitchest renders an MP4 with WebCodecs, directly in the browser. No sign-in.

Want to grab a still instead? Use Save Frame PNG to pull a single frame — handy for thumbnails or covers.

Push it further with the Time Machine dial

Once the base look is in place, the Time Machine dial lets you scrub between eras of decay, and an effect box with a fade-in and fade-out eases the effect in and out across the clip. That's useful if you want a clean opening that drifts into full CRT territory by the end.

Keep your text readable

The most common mistake is cranking scanlines so hard that titles turn to mush. A simple fix: keep the scanline opacity low anywhere text sits, and lean on glow rather than density to carry the retro feel. If a title still fights the lines, mask the effect away from that region — Glitchest supports masking so you can protect specific areas while the rest of the frame keeps its full CRT texture. Bright text on a slightly darkened band underneath almost always stays legible.

Pair it with other retro effects

Scanlines rarely travel alone. They stack naturally with a broader CRT treatment and with tape artifacts for a heavier vintage result. If you want the complete tube-TV package — barrel distortion, glow, and color bleed — start with our guide to adding a CRT effect. For a warmer, more analog tape look, combine scanlines with the steps in adding a VHS effect to video. Layering the two gives you that "recorded off the TV" quality that neither achieves on its own.

Scanlines are one of the fastest ways to shift a clip's mood, and the whole process is free and local. Load a clip, dial the intensity to taste, protect your text, and export a clean MP4 — no upload, no strings.

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