Yes, the search looks for an exact match of the entered fragment, including case – "Text" and "text" count as different strings. To replace every case variant, they need to be entered one at a time.
Before a bulk replacement it is worth checking whether the fragment being searched for also appears inside another word, where the replacement would be unwanted: for example, replacing "cat" with "dog" would also affect the word "category". The shorter the fragment being searched for, the higher the risk of that happening.
No, the form works with an exact text match, not with regular expressions or wildcard patterns – replacing every number in a text by a mask in one pass is not possible, only the specific string entered.
The form is built for one "find and replace" pair per run. For several different replacements, the operation needs to be repeated in sequence for each pair.
The text stays unchanged – the replacement only happens where there is an exact match, and no error occurs if there are no matches.
Paste text into the "Content" field, enter the fragment to search for in the "Find" field and what to replace it with in the "Replace" field – the tool replaces every match at once.
After replacing, it is convenient to compare the result with the old version right away using the diff checker, and the text cleaner helps check that the replacement did not leave any double spaces behind.