(Tools, that I personally use/have used and recommend are marked with a heart)
1. LucidChart (♥)
- My favorite diagramming tool
- Cloud-based
- Has a free plan with limited features
- Paid plan starts from US$ 7.95/user/month (7 days free trial)
2. Draw.io
- Cloud-based
- Free
- Cloud-based & desktop-based
- Paid subscription plan starts from US$ 5/user/month (Free 7 days trial)
- Desktop application starts from US$280
4. Omnigraffle
- Desktop-based
- Available on Mac, iPad, and iPhone
- Paid
- US$ 249/license for Mac (Free 14 days trial)
- US$ 119/License for iOS (Free 14 days trial)
5. Creatly
- Cloud-based & Desktop-based
- Has a free plan with limited features
- Paid plan starts from US$ 4/user/month (30-day money guarantee)
- Desktop application starts from US$ 75
6. Gliffy
- Cloud-based
- Integration with JIRA & Confluence
- Paid plan starts from US$ 7.99/user/month (14-days free trial)
7. SmartDraw
- Cloud-based
- Paid plan starts from US$ 9.95/user/month
Don’t see the tool of your choice listed here? Please feel free to mention it in the comments below for other readers’ benefit.
Want to see a list of more of such useful resources & tools under different categories? Please do take a look at the resources page.
OMG! I can’t believe you didn’t include https://elements.cloud/ in your list. It has a quite nice tool for drawing process diagrams. And a lot cool stuff for Salesforce admins and architects.
For sequence diagrams I use (obviously): https://sequencediagram.org/