Kalendar.work is a 100% free, open-source Calendly alternative in 2026, delivering premium scheduling features without subscriptions. Create unlimited event types, add custom branding (logo/colors), two-way sync with Google Calendar & Outlook, branded email notifications/reminders, flexible availability rules (buffers, notice periods), easy reschedule/cancel, time zone auto-detection—all in minutes with no vendor lock-in. Self-hostable for full control; ideal for freelancers, consultants, small teams, and anyone ditching $15+/mo paid schedulers.