nomnoml vs WebSequenceDiagrams (2026): which should you pick?
As of Nov 13, 2026, nomnoml grades higher than WebSequenceDiagrams: 2.8 against 2.4 out of 4.0.
Checked Nov 13, 2026 · graded Nov 13, 2026 by ToolGPA
nomnoml grades higher on value for money and the free plan. WebSequenceDiagrams grades higher on platforms. They get the same grade on features and ease of use.
Price, platforms and features side by side. The table says where each price was read and when.
WebSequenceDiagrams
Text-to-diagram sequence diagram maker with its own layout engine
Which one is for you
Pick nomnoml if
- Fits if you want a class or flow diagram out of a few lines of text
- Works for developers who embed diagrams through the library or command line
Look elsewhere if
- Skip it if you want a freehand canvas or sticky-note board
- Watch out: saving relies on browser localStorage, which the author says comes with no guarantees
- Not for you if you need accounts, sharing links or real-time editing, as the web app has none
- Too light for teams: no collaboration of any kind is listed
Pick WebSequenceDiagrams if
- Fits if you write sequence diagrams from text inside VS Code
- Works for a team of five or more that needs one block of Pro accounts
Look elsewhere if
- Skip it if you want freeform whiteboarding: it draws sequence diagrams only
- Tight if you stay free: wider diagrams and PDF or SVG export are Pro
- Pricey if you pay monthly: $15 against $10 billed annually
- Watch out: WSD Team is a block of 10 accounts at $699 a year, and Enterprise Server is $5,999 plus 20% yearly
How we grade them
| 2.8GPAnomnomlGood | 2.4GPAWebSequenceDiagramsFair | |
|---|---|---|
| Value for money | AFree, open source and available as a library and a command line tool as well as the web app. | CWSD Pro is $10 a month billed annually, $15 monthly, against $8.25 in the middle for whiteboard tools. WSD Team is $699 a year for a block of 10. |
| Free plan and trial | AFree outright, with no sign-up, cap or paid plan. | BWSD Basic is free and lets you save your work and see revision history. The edge is paid: wider diagrams, PDF and SVG export and no branding. |
| Features | CClass, component and flow diagrams from text, with styling. It does that fully, but it is a smaller job than a whiteboard, with no freehand canvas or sticky notes. | CDoes sequence diagrams fully, plus HAR file analysis and a self-hosted edition. A smaller job than a whiteboard, and branding stays on until you pay. |
| Ease of use | CNo store rating on record. You learn its text syntax first. | CNo store rating on record. You learn a text syntax before the first diagram. |
| Platforms and integrations | CWeb only for most people, plus a library and command line. No integrations are listed. | BWeb, with a VS Code extension and AI access via Claude and GitHub Copilot. No phone app. |
| Best for | UML diagrams drawn from a text syntax | sequence diagrams written as text |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: nomnoml and WebSequenceDiagrams. How we grade
Price against what you get
nomnoml has no paid plan and scores 2.0 out of 4 on features, ease of use and platforms. WebSequenceDiagrams starts at $10 a month and scores 2.3.
WebSequenceDiagrams scores higher, and starts $10 a month higher: the question is whether the extra is worth that to you. Of the other whiteboard and mind map tools on the chart, none scores higher than nomnoml for less, and 22 score higher than WebSequenceDiagrams for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- nomnoml is open source, according to its own site.
- WebSequenceDiagrams is self-hostable, according to its own site.
At a glance
| nomnoml | WebSequenceDiagrams | |
|---|---|---|
| Pricing | Free | Free plan |
| Starts at | Free | $10 per month, billed annually ($15 billed monthly) |
| Free plan | None | WSD Basic: save your work, wider diagrams, revision history and PDF and SVG export. |
| Free trial | None listed | None listed |
| Web | ||
| Made by | Daniel Kallin | Hanov Solutions Inc. |
| Price read from | nomnoml.com | websequencediagrams.com |
| Checked | Nov 13, 2026 | Nov 13, 2026 |
Worth knowing
nomnoml
- It draws diagrams from code only; there is no freehand canvas or sticky-note board.
- Saving relies on browser localStorage, which the author says comes with no guarantees.
- The web app has no accounts, sharing or real-time collaboration.
WebSequenceDiagrams
- It makes sequence diagrams only; it is not a freeform whiteboard.
- Branding is removed only on paid plans.
- The Team plan is sold as a block of 10 accounts, so it suits five or more users.
- Enterprise Server is quoted as a site license with 20% yearly maintenance and is sold through sales.
Key features
nomnoml
- Text syntax with live preview
- Edit the code on the left and the diagram on the right updates as you type, with keyboard shortcuts borrowed from Sublime Text.
- Several UML shape families
- Built-in classifier types cover classes, abstract classes, packages, components, sockets, actors, use cases, states, choices, databases and tables.
- Styling directives
- Directives such as #direction, #fill, #font and #spacing change layout and appearance, and custom classifier styles can be defined and imported from other files.
- Library and command line
- The nomnoml npm package renders diagrams on a web page or to SVG in Node, and npx nomnoml converts a file from the command line.
- Browser-only storage
- The web app is client-side and keeps your diagram in the browser's localStorage, so it is there on your next visit, though the author gives no guarantee.
WebSequenceDiagrams
- Text-based diagrams
- Diagrams are written as text and the engine lays out actors and messages without manual line routing.
- VS Code extension
- An official extension offers live side-by-side preview, syntax highlighting and snippets inside the editor.
- AI through MCP
- Claude, GitHub Copilot or other MCP-compatible assistants can generate diagram syntax that the engine then lays out.
- HAR file analysis
- HTTP Archive files can be converted into sequence diagrams that map cross-origin requests and API calls.
- Self-hosted edition
- The Enterprise Server edition runs on a company's own infrastructure so diagrams stay on the internal network.
Plans
nomnoml
Free$0
The whole editor, the npm library and the command-line renderer are free under the MIT license.
WebSequenceDiagrams
WSD Basic$0
Save your work, wider diagrams, revision history and high quality PDF and SVG export.
WSD Pro$10
per month, billed annually ($120 a year; $15 billed monthly)
Removes WSD branding; adds auto-save, parallel flows, auto-numbering and multipage PDF export.
WSD Team$699
per year for a block of 10 Pro accounts
All Pro features for 10 users, with centralized billing and priority email support.
Enterprise Server Edition$5,999
site license, plus 20% annual maintenance
Hosted on your own infrastructure for air-gapped use, with unlimited internal users; sold through sales.
Ways to pay less
nomnoml
No public discounts listed.
WebSequenceDiagrams
- Annual discount
Save 33% with annual billing
WSD Pro is $10 a month billed as $120 a year, against $15 a month on monthly billing; the pricing toggle labels the annual option as 33% off.
Common questions
Which is cheaper, nomnoml or WebSequenceDiagrams?
As of Nov 13, 2026, nomnoml is cheaper to start with: it is free, against $10 a month for WebSequenceDiagrams. nomnoml is free, and WebSequenceDiagrams starts at $10 per month, billed annually ($15 billed monthly).
Which has a free plan, nomnoml or WebSequenceDiagrams?
As of Nov 13, 2026, both nomnoml and WebSequenceDiagrams have a free plan.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.