Antimemetic message that escapes screen capture

Name: Antimemetic message that escapes screen capture
Availability: InStock
Author: Leftium

by Leftium·May 25, 2026·3 points·0 comments

Visit Project View on HN

AI Analysis

●●SolidWizardryEye Candy

CPU-rendered CRT static at 1000 FPS beats GPU shaders for anti-capture realism.

Strengths

•Achieves 1000 FPS on CPU by optimizing noise grain size and scan line rendering.
•URL parameters expose all customization options directly in the address bar.
•Realistic CRT pixel aspect ratios and palette constraints enhance the visual effect.

Weaknesses

•Doesn't actually prevent determined attackers with external cameras or OCR.
•Novelty wear-off is fast since it solves no real security threat model.

Post Description

The message is clearly visible, but it cannot be screen captured. (Or just pause the effect with click/tap.)

I think this TV static effect is more realistic than others on the web:

- Wide CRT "pixel" aspect ratio

- Larger "grains" (to match low CRT resolution)

- CRT "scan lines" (Toggle with 'C' key)

When I attempted this effect many years ago, it didn't seem possible without GPU shaders. With advances in hardware/JS performance, the CPU can easily blast a higher resolution (2560x1440) at 1000 FPS. (ENTER key to go into fullscreen mode)

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Customize the message with url param: https://fx.leftium.com/static?text=HN

(To see all options: 'U' key copies URL to clipboard and also outputs to dev console.)

Made with SvelteKit: https://github.com/Leftium/fx