PlantUML
Hacker ApprovedRanked 5 of 11 diagram tools by recommenders
Plain-text diagrams with strong control and tooling; the usual caveat is harder setup and no native GitHub rendering.
Plain-text diagrams with strong control and tooling; the usual caveat is harder setup and no native GitHub rendering.
18 people gave an opinion
- recommend it
- 16
- criticize it
- 2
- approval share
- 89%
Recommended in 6 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: not recommended
- July 2026: recommended
- August 2026: not recommended
- September 2026: recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 16 people recommend itNeeds 10 or more, met.
- 8 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 6 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Fine control over output styling
“has been the most customizable and flexible for me”
Comment from 27 Sep 2026 in “Show HN: Reladraw – A diagram language where you decide where to place things” “much more expressive when it comes to styling”
Comment from 29 Jan 2026 in “Beautiful Mermaid” “you have a lot more control over the output”
Comment from 30 Mar 2026 in “I use excalidraw to manage my diagrams for my blog” C4 diagrams built into stdlib
“see Structurizer or plant uml c4 for text portable examples”
Comment from 28 Jan 2026 in “Archyl – The modern platform for C4 model documentation” “I'm a huge fan of both C4 and plantuml”
Comment from 25 Sep 2026 in “Show HN: Whiteboard (YC W26) – An open-source IDE for thoughtful software design” “Plantuml includes C4 in stdlib”
Comment from 25 Sep 2026 in “Show HN: Whiteboard (YC W26) – An open-source IDE for thoughtful software design” Text diagrams better than images
“A better way is to auto-generate e.g., class diagrams using PlantUML or Mermaid.”
Comment from 28 Nov 2025 in “Tell HN: Happy Thanksgiving” “diagrams as code like PlantUML or Mermaid are better than an image!”
Comment from 26 Feb 2026 in “Nano Banana 2: Google's latest AI image generation model”
What people warn about
Each mark is one comment
Fiddly setup and tuning
“every hour I spent fiddling with a Plantuml diagram to get the relation directions”
Comment from 27 Sep 2026 in “Show HN: Reladraw – A diagram language where you decide where to place things” “Plantuml is much more annoying to setup, and doesn't render natively on GitHub”
Comment from 28 Sep 2026 in “Show HN: Reladraw – A diagram language where you decide where to place things” Line routing breaks with many lines
“every hour I spent fiddling with a Plantuml diagram to get the relation directions”
Comment from 27 Sep 2026 in “Show HN: Reladraw – A diagram language where you decide where to place things” “The routing tends to blow up when you have a bunch of lines”
Comment from 7 Sep 2026 in “D2 Is Non-Profit”
Other diagram tools people recommend
The four most recommended other diagram tools, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Mermaid | 93 | 46 | 67% | 12 | — | Approved |
| Reladraw | 28 | 7 | 80% | 1 | — | — |
| SQL to ER diagram tool | 27 | 1 | 96% | 2 | — | — |
| D2 diagram language | 21 | 6 | 78% | 6 | — | Approved |
| PlantUMLThis page | 16 | 2 | 89% | 6 | — | Approved |
What people said
16 of the 20 comments that mention it, newest first. Each links to the original comment.
“Plantuml is much more annoying to setup, and doesn't render natively on GitHub”
“has been the most customizable and flexible for me”
“every hour I spent fiddling with a Plantuml diagram to get the relation directions”
“those tools are mainly built to render static diagrams”
“I'm a huge fan of both C4 and plantuml”
“Plantuml includes C4 in stdlib”
“Mermaid or PlantUML are better/cleaner options.”
“The routing tends to blow up when you have a bunch of lines”
“plantuml is good because of the the tooling around it”
“you have a lot more control over the output”
“They just do not give enough power to format the diagrams in a human legible way.”
“diagrams as code like PlantUML or Mermaid are better than an image!”
“You can even use graphviz/Mermaid/PlantUML for visual agentic workflows”
“much more expressive when it comes to styling”
“see Structurizer or plant uml c4 for text portable examples”
“A better way is to auto-generate e.g., class diagrams using PlantUML or Mermaid.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.