A W-2 is the annual tax form distributed to you by your employer. It is a critical document, and your income taxes can't be completed without it. You may be able to get the form online, but it may depend on whether you are looking for a current or past year's W-2.
Come tax time, you may be able to request that your employer send you electronic copies of your W-2. Whether or not it will do so really depends on the company you work for; regardless, it will need to furnish you with paper copies in January or February. Some employers give employees access to current W-2 forms electronically on their website.
W-2s for Past Years
If you are looking for a past year's W-2, you may be able to get it from your employer. If not, you can get it from the Internal Revenue Service. Information from W-2s up to 10 years old can be obtained in PDF form for free from the IRS using the Get Transcript Online tool on the agency's website. To obtain actual paper copies of your W-2 from a past year, you will need to pay a fee, which is $50 as of publication, and request a copy of your entire tax return for that year.