When comparing UltraEdit vs Synalyze It!, the Slant community recommends Synalyze It! for most people. In the question“What are the best hex editors for Mac?” Synalyze It! is ranked 4th while UltraEdit is ranked 6th. The most important reason people chose Synalyze It! is:
You can even add your own grammar for a new file type structure. Great for analysing foreign file formats.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Handles large files (>1GB) extremely well
UltraEdit has small memory usage and allows for fast parsing/searching when handling large files.
Pro Works perfectly with remote files
Supports several protocols for accessing remote files and working on them with the same ease as local files. Files can be integrated in the projects as normal files.
Pro Probably the most versatile general editor in existence.
If you need a general editor, UltraEdit is the way to go. If you were writing C/C++ all day, then this would be your editor. If you need to slog through large files then this is your go to editor. If you need to go through XML files, then this is your editor. If you need to sort data, then this your my editor.
Pro Fast, stable, easy to use
It loads with a short delay, but once loaded it's snappy and rock-solid. Anyone accustomed to using Windows text editors will feel at home in its interface, and those that prefer alternate keybindings can easily change them.
Pro Search and replace capabilities
From Ultraedit to Perl to Unix regex engines, the search and replace can accomplish just about anything.
Pro Responsive company
Whether for feature requests, technical support or license questions, IDM is always quick to respond.
Pro Nice hex display & edit
There's a handful of other features like this that make UltraEdit indispensable.
Pro Extremely customizable GUI editor
UltraEdit offer the best of both worlds. it has a full on GUI along with all the shortcut commands you need. There's no need for the user to suffer 80 char limitations of a terminal editor.
Pro Highly flexible
UltraEdit allows you to handle groups of files as a project.
Pro Can decypher the internal structures of many files, such as .zip, .tar and many "savegame" files
You can even add your own grammar for a new file type structure. Great for analysing foreign file formats.
Pro Advanced binary comparison
Compares binary files byte-by-byte or with a more flexible algorithm that shows inserts and deletions in any of the compared files.
Pro Edits files of unlimited size
Huge files can be opened and edited instantly because only the displayed part is loaded to memory.
Pro Scriptable with Python and Lua
The script engines allow you to automate repetitive tasks and extend the standard functionality.
Pro Can check and monitor checksums of selected text
Selecting a bit of source code and using th e"Show Checksums" feature allows seeing different checksums for selected text and get it updated in real time.
Pro Allows color-coding text
The editor allows selecting a bit of source code and highlight it.
Pro Histogram view
The histogram shows the distribution of all byte values in the file. This lets you quickly see if a file is compressed or encrypted.
Pro Compares text encodings
This feature lets you compare the text representation of a byte sequence for numerous text encodings. This is the most efficient way to find the correct text encoding, be it ASCII-based, EBCDIC or any other code page supported by libICU.
Pro Incremental search
The search results are immediately highlighted in the hex editor. Text, numbers, and masks can be searched.
Cons
Con Proprietary
It's not free and a license costs $79.99.
Con The themes introduced in version 20 regressed certain aspects of syntax coloring
The themes simplified the syntax highlighting which lost the capacity to have as many colors as one wanted to define. Now it is limited to around 20 different colors. In general it's not a problem but in certain cases it broke coloring.
For some reason, the classic theme is the only one that is totally pleasant for readability well with syntax highlighting.
Con Doesn't work anymore
MacOS Monterey changed where python is located, and it crashes when it tries to find it now.
Con Not free
Cost 9.99$ once with 14 days trial (non pro full version).
Con Proprietary
It's closed source.
