OneTimeSuite Blog · 2026

5 Free & Open-Source Alternatives to Calendly

Looking for a free or open-source alternative to Calendly? Bookslot is the closest direct swap — MIT-licensed source on GitHub, or a $39 one-time packaged install. Since you're already auditing what you pay Calendly every month, here are four more pay-once tools from the same catalog worth a look while you're at it — different jobs, same idea: buy the software once instead of renting it forever.

1. Bookslot — replaces Calendly

The Calendly you actually own — timezone-correct booking with email + ICS invites. $39 once vs Calendly's $10/user/mo. Free on GitHub, or the packaged installer on Whop.

See Bookslot → · Source on GitHub

2. Formforge — Typeform-style forms with unlimited responses, file uploads and CSV export — self-hosted.

Replaces Typeform ($29/mo). $39 once. See Formforge →

3. SigCraft — Email-safe HTML signatures with 10 templates and team CSV batch export — 100% local.

Replaces WiseStamp ($6/mo/user). $15 once. See SigCraft →

4. PostDock — Self-hosted social scheduling — composer, queue, content recycling & webhooks. Your API keys, your data.

Replaces Buffer ($6/channel/mo). $49 once. See PostDock →

5. Scantrail — Self-hosted dynamic QR codes with scan analytics, a design studio and batch CSV generation.

Replaces QR Tiger ($15/mo). $24 once. See Scantrail →

Why this list is worth bookmarking

Every app above is a one-time purchase with MIT-licensed source, no accounts with us and no telemetry. None of them are trying to be the next Calendly — they're trying to be the last subscription you pay for that specific job.

Try Bookslot — $39, once

The Calendly you actually own — timezone-correct booking with email + ICS invites.