Skip to content

Shadow

Encrypted, on-device form autofill. AES-GCM, and nothing leaves the browser.

PrototypePlatform: Chrome extensionLast updated July 28, 2026

In one sentence

Encrypted, on-device form autofill. AES-GCM, and nothing leaves the browser.

The problem

Autofill is convenient and most implementations sync your details to somebody's server. For test data, throwaway signups and repeated form work, that trade is not worth making.

Why I built it

Reviewing 200 products means signing up for 200 products. I needed fast, disposable, private form filling.

Who it is for

People who fill the same forms constantly: reviewers, QA, anyone testing signup flows.

Current status

Prototype

Built and in use by me, but no public install or demo link has been verified.

Screenshots

Screenshots pending — real captures only, never mocked.

Technology

  • TypeScript
  • Chrome MV3
  • WebCrypto AES-GCM
  • IndexedDB

Role

Sole developer.

What I learned

WebCrypto in an extension is straightforward; key lifecycle is not. Where the key lives, and what happens to the data when the user clears it, is the entire design.

Public links

There is no public link for this project yet. It is not on a store, there is no hosted demo, and the repository is private — which is exactly why it is labelled a prototype rather than live.

Last updated