Impact estimates are approximations
The numbers Witness shows — lives saved, healthy years gained, units delivered, cost-per-life — are estimates derived from public cost-effectiveness analyses published by GiveWell. They represent averages across programs and years; the impact of any individual gift can be higher or lower. See our methodology page for the exact formulas.
Witness is independent
Witness is an independent project. We are not affiliated with, endorsed by, or sponsored by GiveWell®, the Clear Fund, Malaria Consortium, Against Malaria Foundation, Helen Keller Intl, New Incentives, or any other organization referenced in the app. All trademarks are property of their respective owners.
Not financial or tax advice
Witness does not provide tax, accounting, financial, or legal advice. Charitable-giving tax treatment varies by jurisdiction and personal circumstances. Consult a qualified professional before making donation or tax decisions.
Not a donation processor
Witness does not accept, hold, or transfer money. We do not process payments. To donate, please go directly to the charity's own website.
Currency display only
The currency selector in your profile changes the displayed symbol only. Historical amounts are not converted at live FX rates. Treat the values as approximate when comparing across currencies.
Open-source attribution
Witness is built with permissively-licensed open-source software, including:
- React and TanStack Start (MIT)
- Tailwind CSS (MIT)
- shadcn/ui components (MIT)
- Lucide icon library (ISC)
- Inter and Plus Jakarta Sans via Google Fonts (OFL)
Full license texts are available from each project's repository. If you believe content here infringes your rights, please contact us via the form on your profile and we'll respond promptly.