HumanStamp, by sumedhakethini, is a Chrome extension that proves human authorship and sender effort for email messages. It monitors typing activity in real time, cryptographically signs messages that meet majority-human-typed criteria, and inserts a visible badge recipients can validate within Gmail and Outlook web composers. It adds tamper-evident indicators and a recipient verification portal. Aimed at professionals, job seekers, and students, it helps mark personally written outreach versus AI-generated or pasted content.

How it verifies that a message was actually typed by a person

The extension observes keystroke timing and composition patterns to separate manual input from pasted, AI-produced text, then produces a sealed authenticity marker the recipient can inspect. During composition the tool watches the writing process rather than the final text, and it produces a visual badge attached to the message so recipients have a clear sign to check when evaluating authenticity.

How the extension treats typing signals and message content

The developer discloses the tool focuses on the act of typing rather than storing message bodies, using real-time monitoring to determine a majority-human-typed threshold. Messages that are primarily pasted from generators do not qualify for a seal, and tamper-evident checks alert recipients if a signed message changes after stamping. Recipients with the verification option can view cryptographic proof attached to the badge.

Who benefits from it and where adoption matters most

This is aimed at professionals, job seekers, and students who send high-impact outreach such as cover letters or thank-you notes and want a detectable signal of personal effort. The extension runs in Chrome across desktop platforms, but its usefulness depends on composing in the browser and recipient access to verification tools; uptake among recipients determines how often the stamp actually influences trust in an inbox.

A focused choice for senders who need to prove personal effort

HumanStamp is a targeted assurance mechanism for people who compose important messages directly in the browser and need a verifiable signal that they wrote them personally. Its main trade-off is reliance on sender discipline and recipient-side verification to realize value. Practical tip: compose critical outreach inside Chrome and avoid pasting generated text so the message remains eligible for human verification.