Both PTE and IELTS are essentially language tests with some significant differences. Here are some basic differences.
IELTS is typically a paper-based test conducted by British Council and IDP. Though IDP offers computer-based IELTS still the evaluation of Speaking and Writing module is done manually. That means the IELTS essays, letter writing, speaking part-1, part-2, part-3 are manually evaluated. Where in PTE Academic all the modules answers including speaking and writing are evaluated by the computer.
Typically IELTS takes 13 days time to send the score reports to the test -takers. Where in PTE Academic takes only a few hours to 5 working days to generate the report ( this is one of the reasons why many choose PTE over IELTS)
Both tests are more or less of the same duration IELTS standard test duration is Two Hours Forty-Five Minutes including Listening: 30 minutes, Reading: 60 minutes, Writing: 60 minutes, Speaking: 11-14 minutes. But the fundamental difference is in IELTS the test taker has to visit the temporary test center ( usually a hotel) twice that is once for speaking and then one more time for remaining modules.
Similar to IELTS PTE Academic is also consumes around 3 hours duration. Here is the split of the duration Speaking around 30 minutes, Writing 40-60 minutes, Reading: around 30-40 minutes and listening around 40-60 minutes. In PTE the test taker has to take the test in an authorized Pearson VUE test center which is managed by Pearson the test will be a single sitting type with an optional 10 minutes break.