In this article, I will be listing some of the top tools for drawing ER diagrams online. Priority will be given to ease of use, user experience, and functionality.
An entity relationship diagram, or ER Diagram (ERD), is a visual model of your database schema. It describes the database structure and helps conceptualize how pieces of data interact with one another across a robust database. To some extent, ER diagrams look like flowcharts; they show the database tables as rectangles, with connecting lines representing the relationships between tables through primary and foreign keys. ERDs are an effective way of designing a new relational database or modifying an existing one. For this reason, they are extremely important in database design and in projects that require a clear understanding of the data structure.
To draw an ER diagram, you need to identify all the entities (i.e. tables), know the relationships between them (through the keys), and add attributes (i.e. columns) under each entity. So, if you are designing, patching, or even debugging relational databases, you will likely be looking to generate ER diagrams online; this will allow you to conveniently visualize your schemas while detecting and correcting flaws early on in the process. Creating an ERD before delving deeper can help save time, missteps, and frustration for software engineers and database architects later down the line, too.
Top 9 Online ER Drawing Tools
There are many diagrammatic tools that can be used to create an ER diagram online – but only a few get it right. So, we’ve put together a list of the top nine online ER diagram tools that will help you construct the relational and logical structure of a database.
The database modeler offered by Vertabelo lets you create and edit physical ED diagrams online. This tool supports different ERD notations including crow’s foot, Unified Modeling Language (UML), Barker’s, and IDEF1X.
Vertabelo also supports a whole host of databases, including (but not limited to) PostgreSQL, IBM DB2, Oracle Database, Microsoft SQL Server, MySQL, Amazon Redshift, and BigQuery. You can create SQL DDL scripts (which are used to create tables and other structures in a database) from the physical models. Moreover, you can also generate migration scripts between different versions of the same diagram.
Easy collaboration is a standout feature of the Vertabelo database modeler. This gives multiple users different roles (Owner, Editor, Viewer) and enables them to simultaneously develop and edit diagrams – kind of like a Google Colab for database modeling. When the model is opened for editing by one user, it becomes read-only for the others. Once it is saved, everyone can see the changes in the model. You can also share the model through a link.
The reverse engineering tool and auto layout features allow users to automatically transform existing database projects into visual models through a simple command-line Java application. Another aspect of the modeler that contributes to the seamless workflow is the live validation feature, where Vertabelo validates the model at frequent intervals and provides suggestions, recommendations, and error flagging.
Another web-based tool is Draw.io. Surprisingly, registration is not required for new users. This free tool provides options to store your database models locally or on Cloud storage (including Google Drive and Dropbox). And if you are part of a software development team, you will find Draw.io’s integration with productivity programs like Trello, Jira, and Confluence a very useful feature. Multiple languages are available when using the tool.
Unlike Vertabelo, Draw.io does not appear to support SQL DDL script generation. A list of supported database engines is not specified on the website either. I’d say this makes Draw.io only a drawing app and not a complete ER diagram tool.
Gliffy provides a web-integrated diagrammatic tool with remote collaboration functionality. Users can track versions and revert to prior outputs. Besides collaboration and change control, Gliffy enables users to import images or export diagrams and embed them into popular tools such as Slack. It also offers an app that integrates with Jira and Confluence. There’s a limited time free trial that lets you try the tool before requiring a monthly paid subscription. Like Draw.io, Gliffy lacks SQL DDL functionality or any clear specifications of the database engines supported by the web-based tool.
With Visual Paradigm, you can swiftly create database structures by accessing hundreds of templates, including ERDs. Even its free version allows you to create unlimited non-expiring diagrams and export them to watermark-free images.
Visual Paradigm is a popular desktop ER diagram app that now lets users draw ER diagrams online. However, I found the web tool a bit cumbersome to use. Still, it supports database design, database generation, and ERD reversal for most popular database engines. You can export files to images or PDFs or import to MS Visio or MS Office. There’s integration with Word, Excel, and OneNote. There are also remote collaboration capabilities, but SQL DDL generation is only supported through the desktop app.
SqlDBM provides an online data modeler and diagrammatic tool with version control. It can identify errors and discrepancies and filter through attribute and field types like nullability, data type, and defaults. The availability of dark and light themes as well as flexible viewing modes adds a much-needed dimension to the user experience. It supports Microsoft SQL Server, MySQL, and PostgreSQL, but you will have to opt for the second tier of its paid version for access to Snowflake, Amazon Redshift, and Azure Synapse Analytics or if you want remote collaboration capabilities.
DrawSQL is a simple, sleek, well-designed online tool for manually building your ER diagram or importing it from an existing database. Having moved over from their initial ‘DBMS agnostic’ approach, which initially posed some limitations, DrawSQL currently supports MySQL (MariaDB), PostgreSQL, and Microsoft SQL Server. They have a template gallery with over 200 samples, plus something called ‘presentation mode’ that lets you annotate tables and columns and share read-only versions. It’s especially useful for explaining things to your broader developmental team.
ERDPlus is a web-based database modeling tool. You can build your ER diagram and then automatically convert it to a relational schema by generating DDL statements, which generate SQL from the diagram. You can then export diagrams as image files. ERDPlus works with most contemporary RDMS, including Oracle, MySQL, Microsoft SQL Server, PostgreSQL, Teradata, IBM DB2, and Microsoft Access. Although ERDPlus does have a dated user interface, it is held in a quite high regard in the industry.
If you are curious about an alternate approach to making ER diagrams, then check out QuickDBD. It provides a simple type-to-create approach, where you can basically create the ER diagram by typing out the SQL code. With the typing-oriented approach to developing database structures, QuickDBD occupies less RAM and has a comparatively lighter weight GUI. However, the vast majority of users still prefer UI-based tools, since they don’t require you to memorize SQL syntax!
You can also share your diagrams online with teammates to work collaboratively and develop a quality database structure. QuickDBD supports importing schema from databases including MySQL, MariaDB, Oracle, and SQL Server. The only drawback with the free version is that you only get one ER diagram with a maximum of 10 tables.
DBDiagram.io is yet another tool for creating ERDs online. Like QuickDBD, DBDiagram produces diagrams through writing lines of codes, which is definitely favored by users who enjoy editing via the keyboard. The free version allows users to export diagrams as images or PDF files and share them through links. Furthermore, it gives you the ability to integrate with popular web frameworks like Rails or Django by simply uploading the schema.rb or models.py files. Currently, it supports database imports from MySQL, PostgreSQL, SQL Server, and Rails (schema.rb).
ERDs Online and Off
There we have them – the nine most useful tools for generating ER diagrams online. The one you should choose will depend on what you’re hoping to achieve.
The first seven tools allow you to draw ERD through a web-based GUI with varying degrees of functionality. In other words, you can sketch ER diagrams using drag-and-drop features. Although most of the tools here are pretty much all-inclusive, the Vertabelo data modeler is built for developing ERDs online, while most of the others have ERD as one of their features. On the other hand, if you happen to be someone who prefers to create ERD without leaving your keyboard, the two last solutions may be the best options.