It depends on whether your work can be looked at. A designer or developer without a portfolio is asking the reader to take their word. An accountant is not.
A portfolio helps most when
- Your output is visual or interactive: design, front-end, video, writing, photography.
- You are early in your career and your work history is short.
- You are changing fields and need to show skills your job titles do not.
- You freelance and clients want proof before they write.
Field guides: developer portfolio website and data analyst portfolio website.
A resume alone is usually enough when
- Employers screen on credentials and years, as in finance, law and nursing.
- Your work is confidential and cannot be shown.
- The application only accepts a file.
Even then, a one-page site with your summary, roles and contact details gives you a link to put in your email signature and LinkedIn profile. It costs an afternoon.
If you have nothing to show yet
Make something small and finish it. A case study of one real problem you solved, a redesign of a page you use, a short write-up of a project from class. One finished piece beats five outlines. If you are a student or recent graduate, see what a fresher's portfolio should show.
Keep both
Applicant systems read files, so send a clean PDF with the application and put the site link at the top of it. Check the PDF with the free ATS scanner.