Adapting WhatsApp Lists to bring Icons to Volt users

We’re excited to share a small but meaningful improvement in Volt: you can now personalize your lists with emoji icons. 🎉

What started as a fun UX idea (helping users recognize and express their lists more easily), led us to explore some creative encoding techniques under the hood.

Encoding Emoji in List Names

To keep things simple, lightweight, and compatible across devices (especially with mobile WhatsApp), we decided to embed the emoji directly in the list name.

A special invisible character acts as a marker to indicate where the emoji begins, so Volt can render it correctly while WhatsApp can also render it in the native app.

Hiding Emoji When a List Is Archived

When a list is archived, its emoji icon transforms into the 📥 (inbox) emoji. We didn't want to pollute the UI with multiple emojis.

But here’s the trick: the original emoji isn’t gone. It’s just hidden, preserved invisibly using Unicode characters.

We use a binary encoding scheme:

• \u200B (zero-width space) represents 0
• \u200C (zero-width non-joiner) represents 1

This lets us store and later recover the original emoji, while showing only the archive icon in the meantime. The result is a subtle but satisfying visual distinction between active and archived lists.

Bonus track: A ZWJ Surprise 🧩

During development, we ran into a tricky bug.
Initially, we used the Zero Width Joiner (ZWJ) as the invisible mark for signaling where the emoji icon starts. It worked fine, until we tested with emojis that also use ZWJ internally to create composite emojis (like family emojis or gender variants).

The result? Some icons broke apart and displayed incorrectly.

To fix this, we switched the invisible mark to the next invisible character, \u200E (Left-to-Right Mark), which safely indicates the emoji boundary without interfering with ZWJ-based emojis. It’s one of those subtle emoji lessons you only learn the hard way.

Why It Matters

Tiny design details like this make a big difference.
By showing an expressive emoji when a list is active, and a minimalist inbox icon when it’s archived, Volt feels more intuitive and emotionally responsive.

It’s a small touch.. But one that makes the experience feel more personal, polished, and alive!