When comparing OmniDB vs pgAdmin 4, the Slant community recommends OmniDB for most people. In the question“What are the best GUI tools for PostgreSQL on Windows?” OmniDB is ranked 4th while pgAdmin 4 is ranked 6th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open source and actively developed
Pro PL/pgSQL Debugger
Pro Web-based, can be run locally or deployed on server
OmniDB is web-based and works similarly to pgAdmin 4. You can run the web server locally or deploy it on a server, and connect to it through a web browser.
Pro Multi-database
Supports PostgreSQL, Oracle, MySQL and MariaDB, with support in the pipeline for Firebird, SQLite, SQL Server and DB2.
Pro Simple and intuitive interface for everyone.
An easy-to-discover tree panel to classify features/objects on left (with context menus if you don't know what you're doing). Tabs panels for ins and outs on right. That's it.
Pro OmniDB has 2ndQuadrant as its main sponsor
Pro Open source
pgAdmin is open source and actively contributed to.
Pro Dashboard displays useful overview of server activity
The dashboard tab includes server load visualizations and other useful details on database activity, such as connected sessions, database locks, and prepared transactions.
Pro Can be deployed on a server and accessed remotely from browser
As pgAdmin 4 is a web application, it can be easily deployed on any server and accessed remotely using any web browser.
Pro UI can be re-organized to user's liking
pgAdmin 4's user interface elements are detachable panels that can be dragged around and re-arranged to be displayed standalone or in the tabbed browser.
Pro Tabbed views to accomodate different screen/window sizes
The tabbed browser in pgAdmin 4 is excellent for accomodating different screen/window sizes. If you're on a small screen, the tabbed browser can save you screen estate by displaying the different panels in different tabs. If you're on a big screen, you can make full use of your screen estate by detaching the panels and moving it where you like.
Pro Portable version available
There is a portable version of pgAdmin available, pgAdminPortable that allows you to easily move your info between machines.
Cons
Con Resource intensive
pgAdmin4 is a web application. The native binary is a wrapped version of the web app that runs a webserver and web browser, thus it has a high memory footprint and other possible impacts on system resources a native application wouldn't have.
Con UI is slow
The user interface is slow, especially when interacting with query results. While queries execute fast, the user interface can lag behind — selecting a row from a table, scrolling through data, and performing other UI operations can have some delays.
Con UI for Mac is very different from other Mac apps
The file navigation seems homegrown and is very hard to use. It resets you to the root directory every time you open a new file browser. Actively frustrating to use.
Con Bloated
900MB installed, and for an unintuitive, and feature-lacking software.
Con Lack of a schema - sql option
Con Not Intuitive
Dated and obtuse UI design.
Con Non-native UI
Many "normal" key bindings don't work like in other apps. Scrolling behavior is terrible.