So Kaitai Struct (http://kaitai.io/ http://kaitai.io/ - they have a web IDE) isn't a hex editor, but their IDE is what I'd jump to if I had to pull apart a blob

So Kaitai Struct (http://kaitai.io/ http://kaitai.io/ - they have a web IDE) isn't a hex editor, but their IDE is what I'd jump to if I had to pull apart a blob of binary data. You define the schema and it automatically turns the data into a labeled tree you can click through without needing to remember offsets or byte patterns or whatever. You can use the schema in a number of programming languages then, and if you wanted to compare files it might be a few more steps but you could export your data as json and get a semantic diff vs "4 bytes changed at offset 1294".