Word document (.doc or .docx)
Submitting your CV as a Word .doc or .docx file is one of the most popular choices for many candidates and hiring companies. It's the default file type for CVs as basically everyone can open and read a Word document, which means the likelihood of the recipient receiving and being able to access your CV is high.

Pros:

A Word document is the standard and most popular format for most CVs

All applicant tracking systems can read Word documents

Cons:

There are some minor formatting differences between Word documents on a Mac versus a PC. This can potentially disrupt the formatting on your CV template if a recruiter or hiring manager opens your Word document on a different operating system

PDF
Along with Word files, PDFs are a common option. PDFs are a great choice for a number of reasons. Most notably, they eliminate the risk of sending a virus-infected file, and they preserve your formatting so that the recipient will receive your CV exactly as you saved it. However, PDFs are also not without their faults, the main offender being the lack of compatibility with some applicant tracking systems. 

Pros:

PDF documents are compatible with both Mac and PC operating systems

Sending a PDF eliminates the risk of viruses

Saving your CV as a PDF file ensures that the formatting stays as is, and no changes can be made to the document

Cons:

Some ATS software systems cannot read Adobe PDF format documents. If you send a PDF that the ATS can't read, your CV may never reach the recruiter or hiring manager.

Plain text
A plain-text file (or a txt file) is not as commonly used for CVs as Word documents or PDFs. One of the main reasons for this is that plain-text file types are devoid of any formatting elements or text effects such as bold text, italics, indents and spacing. Presenting your CV without structure or formatting can make it uncomfortable for the recipient to read. Despite this, there are still a few benefits of choosing plain text for your CV.

Pros:

You can place a plain-text CV within the body of an email, rather than sending it as an attachment

All applicant tracking systems are able to read and parse plain-text files

Cons:

Submitting your CV in plain text means all spacing will disappear. This can make your CV hard to read

Plain text strips out text formatting such as bold text and italics, so some of the points that you wanted to emphasise on your CV may get lost

HTML
If you think you need to be a tech guru to save your CV as an HTML file, think again. In recent years, it has entered the world of CV submission. These can be sent as email attachments that open directly in the recipient's browser, as well as posted to a website or online portfolio. 

Pros:

The hiring manager or recruiter can view your CV in their email browser, rather than needing to download it

When sending a CV as an email attachment, the HTML format retains the format and layout

Cons:

Some browsers do not support HTML documents

Your CV may be marked as spam in the recipient's email browser, as spam is often sent in HTML

Special mention: hard copy
Believe it or not, hard-copy CVs are not entirely extinct. Companies will expect you to bring a hard copy of your CV to your job interview, for instance. Occasionally, companies and hiring managers will actually accept them as an alternative to a digital application. It's a good idea to check the job description or the careers page on the company website to see if the company accepts (or even prefers) hard-copy applications.

Our choice
At TopCV, we recommend a Word .doc or .docx file above all else. This is because of the importance of its two major benefits: maintaining formatting and being read well an applicant tracking system. The design and layout of your CV is essential to making a polished impression, as well as to direct the HR manager's eye to the information that best showcases your value. 

That said, the merit of a PDF file format should not be ignored. It's true that the potential for issues with the ATS makes submitting a PDF a gamble likely not worth taking. However, not all companies use this software. If you happen to know that your CV will go directly to human eyes, a PDF remains a viable option.

Choosing a CV file name
There is another detail regarding saving your CV that too often is overlooked: the file name. Regardless of what file format you've chosen to submit your CV as, the recruiter or HR manager will see its name. Therefore, you must take care that it is neither unprofessional nor confusing.

Generic titles that make sense on your own computer may be unclear to a new reader, so avoid names like 'cv.doc' or 'updatedcv2.doc'. Make your CV easy to identify by including your name, such as 'JaneSmithCV.doc'. Be sure to include 'CV' in the file name as well so an HR manager can distinguish your CV from your cover letter without having to open either.

Collected From TopCV