After uploading, the portal filled in my details wrongly. Should I fix them manually?

Yes, always correct the auto-filled fields. Many portals read your resume and copy what they find into their form, and that step often makes mistakes, such as putting a company name in the job title field or mixing up dates.

Check each section:

• Name, email and phone number with country code.
• Job titles, employers and start and end dates for every role.
• Education: degree, institution and dates.
• Skills: remove odd fragments the portal created.

Recruiters often search and filter using these form fields, so accurate fields matter as much as the attached file. Take your time and compare against your resume line by line.

If the same mistakes appear on several portals, your file layout may be the cause. Single-column layouts with standard headings, and each job's title, employer and dates kept together, tend to be read more reliably. Some portals let you skip the automatic reading and type the details yourself; that is fine too, and sometimes faster than fixing a badly parsed form.