Free for personal use. $24 a seat for commercial.

One paid tier — Line9 Pro. Per seat, with a floor of one: $24 a month, or $240 a year (two months free). A workspace with one member is just a workspace; the team-shape is there if and when you need it.

Free

The web viewer, the MCP, and a personal-use CLI.

$0 — forever, no card
  • Web viewer with custom rendering, all standard themes, SVG/PNG export.
  • URL-hash sharing — diagrams live in the link, not on a server.
  • MCP for ChatGPT, Claude and Grok: renders diagrams on demand, no account needed, watermark embedded.
  • CLI for personal use: hobby projects, side projects, learning, OSS contribution.
  • Watermarked exports (a small line9.ai mark, unobtrusive).
Open the viewer → Get the CLI →

Pro

Commercial-use CLI, published diagrams, watermark removal.

$20 per seat / mo · billed $240/yr
  • Commercial-use licence for the CLI — full Pro features in agent and CI workflows.
  • Private workspace with published diagrams at line9.ai/d/<slug>.
  • Watermark removal on every export.
  • MCP: list and show diagrams from your workspace, with clean renders.
  • Embed-ready output for Notion, Confluence, READMEs.
Start with one seat →

Compared, side by side

FeatureFreePro
Web viewer + custom renderingYesYes
Standard themesAllAll
Pro themesPreviewKingfisher
SVG / PNG exportYesYes
URL-hash sharingYesYes
Published share URLs (line9.ai/d/…)—Yes
Watermark on rendered outputVisibleRemoved
CLI for personal useYesYes
CLI for commercial use—Yes
MCP rendering in chat appsYesYes
MCP: list and show workspace diagrams—Yes
Embed-ready output—Yes
Workspace + team seats—From 1 seat

Try at work, then upgrade

The personal-use EULA grants a brief commercial-evaluation window so you can render diagrams at work before going Pro. No key, no countdown, no tracking — just honest cover for the natural "try it before we buy" flow.

See the EULA for the exact terms.

Billing

Billed monthly or annually; cancel anytime. Stripe Tax is applied on every invoice.

$24 / seat / month · $240 / seat / year