JargonLens

YouTube jargon jargon 0:02 Specialist terms that make expert videos hard to follow. JargonLens explains them — like this — right on time. , explained while you watch

JargonLens reads the captions of the video you're watching and shows a plain-English definition the moment each specialist term is spoken. No pausing, no second tab.

Add to Chrome — free

Chrome & Edge · English videos with captions · Free

JargonLens running on a YouTube video about Kubernetes: definition cards for 'cluster' and 'control plane' overlay the player, and the extension popup lists all 12 terms found in the video with a search box.
Definitions appear on cue
A glossary for every video
The real thing: definition cards appear in the player as terms are spoken, and the popup holds a searchable glossary of every term in the video — click one to jump to the moment it's said.

See it work in 30 seconds

Definitions landing on cue, the glossary popup, and the jump-to-timestamp — on a real video.

Timed, not spammy

Each definition appears about a second before the term is spoken, stays 10 seconds, then fades. One card at a time, at least 30 seconds apart.

A glossary per video

Search every term found in the current video and jump straight to its timestamp. Your last 20 glossaries stay available, stored locally.

You're in control

Click a card to hold it, double-click for a longer explanation, and mark terms “I know this” so they never appear again.

Consent first. Local by default.

JargonLens runs only on YouTube, and only after you allow caption analysis. It sends the current video's URL and transcript for analysis — never your browsing history, never audio. Transcripts aren't logged or stored, and your settings live in your browser. Full privacy notice →

Add to Chrome — free