Word count, character count, sentence count and reading time for the rubric in front of you.
For the parts of student life that involve running numbers or hitting word limits: grade percentages, due dates, age gaps for group work, BMI for a health class, length checks against an assignment brief, and the formatting the rubric actually penalizes for. None of it leaves your device until you paste the answer in.
Conventions differ by department and by assignment, and the brief is the authority. The common pattern is that the reference list sits outside the limit while the abstract and in-text citations sit inside it, but appendices are the element everyone gets wrong - ask before you cut a section to fit.
Because the portal counts what it counts: in-text citations, footnotes, tables, hyphenated words and anything after a hyphen are each treated differently by different tools. Trust the portal that enforces the limit, and paste the same text you will submit.
Remove hedges and filler first - the qualifiers that add no meaning, the sentences that restate the previous one, the example you have already used twice. Cut one of two parallel conclusions rather than trimming every paragraph evenly, which leaves the argument intact and the prose tired.