Kontain Reviews & Product Details

Kontain is lightweight invoicing for independent consultants, freelancers, and solo founders. Keep clients, notes, and billing in one place. Create an invoice, share a public link, and the client can view, leave a note, download their PDFs as a ZIP, and pay by card — no account required. Set a monthly, quarterly, or yearly retainer and Kontain creates the next invoice. Save invoice templates to reuse wording and amounts. Log hours and turn unbilled time into a draft invoice. Put several lines on one invoice. Download a branded PDF with your logo. The dashboard shows outstanding, overdue, and paid. Optional AI helpers tighten invoice wording and summarize private notes; you review before anything is saved. Multilingual support; invoice language for PDFs and the public page; timezone for due dates. Export a ZIP of your data and restore it later. 14-day trial, then Starter or Pro.