Best USB LED rope lights

Top pick: Premier Lumen8 12 ft USB-powered color-changing rope. It's the one that does the job you asked for — plugs into any USB port or power bank, 16 colors, and 12 ft is a sensible length for a desk, shelf or headboard without a wall outlet nearby.

Who the others suit:

• 5Ft Portable USB LED Rope Light & Lantern — the camping and power-outage pick: IP-67 waterproof, 180 lumens, runs about 6 hours on its own battery.
• USB Festive Candy Cane rope — short seasonal accent for a window or mantel.
• EL-wire style USB strips — thin, bendy glow for shaping around objects and signs; dimmer, more decorative than functional.
• Ollny 33 ft and GHODEC 33 ft ropes — long runs for a room or patio, but they're mains-powered, not USB.

For anything longer than a few feet, expect to step up to a plug-in rope.