diagram.ch vs OpenCharts

diagram.ch has no write-up on Specifiction yet; its figures are above.

OpenCharts is an AI workspace for flowcharts, presentations, notes, code, video, and agents. Theo AI can create these materials from plain-language descriptions. Flowcharts use terminal, process, decision, and data nodes on an infinite canvas, with automatic layout and export tools. The presentation editor supports editable slides, speaker notes, transitions, AI generation, rehearsal coaching, web publishing, and PPTX export. Theo Agents can start on schedules, webhooks, monitoring triggers, or manually; they can use external connectors, human approval gates, and produce deliverables. Connectors include Stripe, HubSpot, Slack, Google Sheets, Discord, Notion, GitHub, and others. A REST API manages project types, and the Theo MCP server provides 113 tools and five readable resources. Each account starts with 10 GB of Drive storage, including Free Forever. That plan costs nothing and includes 500K AI credits and one of each project type. Starter costs $9.99 a month, Pro $24.99 a month, and Teams $14.99 a month with a three-user minimum. OpenCharts says it does not use customer data to train or fine-tune AI models.