SequenceDiagram.org vs Swimlanes.io (2026): which should you pick?
As of Nov 13, 2026, SequenceDiagram.org grades higher than Swimlanes.io: 3.0 against 2.8 out of 4.0.
Checked Nov 13, 2026 · graded Nov 13, 2026 by ToolGPA
SequenceDiagram.org grades higher on platforms. They get the same grade on value for money, the free plan, features and ease of use.
Price, platforms and features side by side. The table says where each price was read and when.
SequenceDiagram.org
Text-based UML sequence diagrams you can also drag and drop
Which one is for you
Pick SequenceDiagram.org if
- Fits if you draw sequence diagrams and want them stored in your own Drive
- Works for people who want diagrams processed in the browser, not on a server
Look elsewhere if
- Skip it if you want a freeform whiteboard: sequence and architecture diagrams only
- Not for you if you need live co-editing, because sharing is by link or saved file
- Watch out: the code is not open source, and the paid on-prem Docker version has no published price
- Too light for team spaces: there are no accounts or shared workspaces listed
Pick Swimlanes.io if
- Fits if you write a sequence diagram a week and want it from text
- Works for explaining an API call or a login flow to someone with a link
Look elsewhere if
- Skip it if you want a freeform canvas or sticky notes: it draws sequence diagrams only
- Watch out: without an account the web address changes on every edit, so an old link shows the old diagram
- Not for you if your company needs a named vendor and published terms, because the site gives neither
- Too light for teams: no real-time collaboration is listed
How we grade them
| 3.0GPASequenceDiagram.orgVery good | 2.8GPASwimlanes.ioGood | |
|---|---|---|
| Value for money | AFree to use, with a Patreon at $1 a month for donations. Nothing on the page is paid for features. | AFree, with no paid plan listed. It is a web app anyone can open and use, which beats every price in the category. |
| Free plan and trial | AFree outright, with no plan, trial or sign-up needed. Work saves to the browser, a file, Google Drive or OneDrive. | AFree outright: no plan, cap or trial on the page. An account is optional and only collects your diagrams. |
| Features | CSequence and architecture diagrams with export and plugins. A smaller job than a whiteboard, and the listing says it covers nothing else. | CDoes sequence diagrams fully, with flow structures, Markdown, sharing and export. That is a smaller job than a whiteboard, with no freeform canvas. |
| Ease of use | CNo store rating on record. You get a text syntax and a drag-and-drop view to learn. | CNo store rating on record. You write the diagram in a text syntax, so there is a short learning curve. |
| Platforms and integrations | BWeb with Google Drive, OneDrive, Confluence and IntelliJ IDEA integrations. No desktop or phone app. | CWeb only. Sign-in goes through Google or GitHub, and no apps or integrations are listed. |
| Best for | UML sequence diagrams from text or drag and drop | quick sequence diagrams in the browser |
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: SequenceDiagram.org and Swimlanes.io. How we grade
Price against what you get
SequenceDiagram.org has no paid plan and scores 2.3 out of 4 on features, ease of use and platforms. Swimlanes.io has no paid plan and scores 2.0.
SequenceDiagram.org scores higher for the same starting price. Of the other whiteboard and mind map tools on the chart, none scores higher than SequenceDiagram.org for less, and none scores higher than Swimlanes.io 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
- Swimlanes.io also covers Markdown and file sharing.
At a glance
| SequenceDiagram.org | Swimlanes.io | |
|---|---|---|
| Pricing | Free | Free |
| Starts at | Free | Free |
| Free plan | None | None |
| Free trial | None listed | None listed |
| Web | ||
| Made by | NoSpareTime AB | Swimlanes.io |
| Price read from | sequencediagram.org | swimlanes.io |
| Checked | Nov 13, 2026 | Nov 13, 2026 |
Worth knowing
SequenceDiagram.org
- It covers sequence and architecture diagrams only, not freeform whiteboarding.
- The code is not available under an open-source license.
- There is no real-time multi-user editing; sharing is by link or saved file.
- The on-prem Docker version is a paid perpetual license, but its price is not published.
Swimlanes.io
- Without an account, the diagram lives in the URL and the URL changes whenever the diagram is edited.
- It draws sequence diagrams only, with no freeform canvas.
- The site does not name the company behind it or publish terms or a pricing page that we could read.
Key features
SequenceDiagram.org
- Text and drag-and-drop together
- A diagram is described in a text script and can also be edited by clicking and dragging on the drawing.
- Client-side processing
- All parsing, processing and drawing happens in the browser, which the site says means diagram data is not transferred over the internet.
- Saving and sharing
- Diagrams save to a file, Google Drive, OneDrive or browser storage, and a share link can be generated.
- Export
- Export as SVG with the source text embedded, or as PNG; PDF is produced by printing from the browser.
- Architecture diagrams
- Besides sequence diagrams the editor can create architecture diagrams, which need a recent Chrome, Edge, Firefox or Safari.
- Plugins and on-prem
- Plugins exist for Confluence Cloud and IntelliJ IDEA, and a Docker image is offered for internal company use.
Swimlanes.io
- Live text editing
- Edit the text on the left and the sequence diagram on the right updates in real time.
- Markdown in messages and notes
- Messages and notes accept italic, bold, strike-through and inline code, plus lists, links, code blocks and Font Awesome icons.
- Flow structures
- The syntax covers conditional sections with if and else, groups, dividers, delays, automatic numbering and actor reordering.
- Sharing and export
- Diagrams can be shared as a link, short URL, image link or embed, or downloaded as an image or PDF.
- Optional account
- Signing in with Google or GitHub collects a person's diagrams in one place; without it the URL carries the diagram.
Plans
SequenceDiagram.org
Web app$0
The browser editor is free to use; the site invites voluntary Patreon support from $1 a month.
Swimlanes.io
Free$0
The site describes itself as a free web app; no paid plan is listed.
Common questions
Which is cheaper, SequenceDiagram.org or Swimlanes.io?
As of Nov 13, 2026, both SequenceDiagram.org and Swimlanes.io are free to use.
Which has a free plan, SequenceDiagram.org or Swimlanes.io?
As of Nov 13, 2026, both SequenceDiagram.org and Swimlanes.io 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.