I built a Chrome extension that reads SaaS Terms of Service so you don't have to

Romain Loupias — Wed, 25 Mar 2026 10:02:39 +0000

Every SaaS has a Terms of Service. Nobody reads it.

I got burned by an auto-renewal clause I missed. Paid for a full year of a tool I'd stopped using 3 months in. When I went back to read the ToS, the clause was in paragraph 14, written in legal language that would take a lawyer to parse.

So I built Explain Legal, a Chrome extension that does it automatically.

How it works

When you land on a SaaS pricing page, the extension:

Detects that you're on a pricing or checkout page
Silently fetches the Terms of Service from the same domain
Analyzes it with Claude (Anthropic's API)
Surfaces the results in a sidebar — no clicking required

What it shows you

A verdict: Safe, Caution, or Avoid
Up to 3 red flags focused on financial risk (auto-renewal, non-refundable payments, price change rights)
2 questions to ask support before you commit

The technical stack

Chrome Extension (Manifest V3, vanilla JS)
Vercel serverless function as a proxy (keeps the API key server-side)
Upstash Redis for usage tracking (freemium model — 3 free scans)
Claude API for the analysis
Stripe for payments

The interesting engineering problem

The hardest part wasn't the AI analysis, it was reliably finding and fetching the ToS page from any domain. Some sites link to /terms, others to /legal/terms-of-service, others bury it in the footer with non-standard anchor text.

The current approach: scan for anchor tags containing "terms", "tos", "legal", or "conditions" on the same domain, with a fallback to /terms. Works for ~85% of sites.

Try it

It's live on the Chrome Store: Explain Legal

3 free scans included.

Happy to answer questions about the build.

DEV Community: Romain Loupias

I built a Chrome extension that reads SaaS Terms of Service so you don't have to

The technical stack