Delighted charges $224 a month to ask your customers one question and store the answers in their cloud. Pulsecheck does the same NPS, CSAT and CES capture on your own server, with detractor alerts and per-segment breakdowns. $29, once. It is subtraction.

• Three survey types — NPS (0-10), CSAT (1-5) and CES (1-7), each with correct documented score math (NPS = %promoters minus %detractors, ranged -100 to 100).
• Three delivery channels — A standalone survey link, personalized email sends via your own SMTP, and an embeddable widget script.
• One response per recipient — Email-keyed dedupe at the database level means a second submit gets a friendly already-responded message.
• Detractor alerts — A Slack-ready webhook and/or email fire instantly on low scores, and soft-fail so they never block response capture.
• Dashboard — Score trend over time, the promoter/passive/detractor split, and a response feed with comments.
• Segments — Pass tags like plan:pro with responses and get per-segment NPS breakdowns.
• XSS-safe by construction — The public survey page escapes every user-controlled string and the widget renders via textContent only.

Runs as a Windows desktop app or on any $5 VPS (Docker included).

What’s included:

• Full source code (MIT): https://github.com/bensblueprints/nps-survey-tool
• Lifetime v1 updates
• Setup guide (README quick start)