Tailoring is the highest-value thing you can do to a CV, and the checker has a feature built for it: an optional job description box that turns the keyword block into a direct comparison against a specific advert.
Step by step
Open the checker and add your CV
Go to the ATS Resume Checker and upload the CV you plan to send for this role.
Paste the job advert
Expand "Add the job description" underneath the upload area and paste the advert. It is optional, but without it the checker can only judge your vocabulary in general rather than against this role.
TipPaste the whole advert, including the requirements list — that is where most of the terminology lives.
Run the check and read the match
Press Check my CV score. The report gains a Job description match section showing a percentage and two lists of terms: the ones found in your CV and the ones missing from it.
Work through the missing terms honestly
Go down the missing list and ask, for each one, whether you genuinely have that experience. If you do, work the term into the place it belongs — a skill into Skills, a responsibility into the relevant Work Experience bullet. If you do not, leave it out.
TipMatch the advert's wording where it is a fair description of what you did. If it says "stakeholder management" and you wrote "working with stakeholders", use theirs.
Download and re-check
Export the updated CV and run it through the checker again with the same job description pasted in. The match percentage should move.
Keep a copy per role type
Rather than editing one CV forever, keep a version per kind of role in My CVs and tailor from the closest one each time.
Questions people ask
Is the job description required?
No, it is optional. Without it you still get a score; with it the keyword section compares your CV against that specific advert.
Should I add keywords I do not have experience with?
No. Interviews are where that unravels. Add the terms you can genuinely stand behind and leave the rest.
What match percentage is good?
The report calls 70% and above a strong match and 45–69% moderate. Treat it as a prompt to look at the missing list rather than a target in itself.