When viewing an average-size request (few dozens of KB, or hundrers of KB), display performance is just horrible.
The Raw Inspectors take several seconds to display the request (plus they redraw multiple times uselessly, which slows down even more).
This is extremely painful when scrolling thru a capture session, searching for or deleting items... a large request will sometimes get the focus and freeze Fiddler for several seconds. Given the number of times the UI is redrawn, it can easily take 20 or 30 seconds to skip a single request.
Please improve display performance for average-size or large requests (or at the very least eliminate useless redraws, and make the slowdown asynchronous, so that the user can switch to another request if they clicked a large one by mistake).
I experience the problem with Fiddler v4.6.20171.9220, on Windows 10.
The main reason why I use Raw inspectors is... because they're there :) I often debug authentication exchanges, and I like having an overview of requests/responses (it lets me see in one glance whether the exchange is correct, and expected headers and contents are there). Multiple formats are involved (some requests are JSON, others are XML, the rest is WebForms) so using other inspectors would mean constantly switching between them.
Since I always use the Raw inspectors, I also sometimes use them to copy the contents of a request or response (I don't want to bother with saving contents to a temp file). There is probably a smarter way to copy to clipboard, but I didn't find it. This means disabling Auto-truncate, and enduring the slowdown if the request/response was large.
Oops, this is actually an exact duplicate of https://fiddler.ideas.aha.io/ideas/FID-I-123.
FWIW, one reason that the RAW Inspectors are so rough is that I never used them, even though I suspect telemetry would show that they're pretty popular.
The Raw Inspectors are among the few remaining Inspectors that don't override the AssignSession() method, but should. That will allow setting the Headers, Body, and ReadOnly state in one shot instead of performing three updates. This should take no more than a few minutes for Telerik to change.
On which platform are you experiencing this problem? Can you share a SAZ file that demonstrates the issue?
Is there a reason you're using the RAW Inspectors vs. the other Inspectors, which tend to be more useful?