UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

the Securities Exchange Act of 1934

June 30, 2013

Date of Report (Date of earliest event reported)

Commission File No. 0-14225

EXAR CORPORATION

(Exact name of registrant as specified in its charter)

48720 Kato Road, Fremont, CA 94538

(Address of principal executive offices, zip code)

(510) 668-7000

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

On July 24, 2013, Exar Corporation (the “Company”) issued a press release announcing its financial results for the first fiscal quarter ended June 30, 2013. A copy of the press release is attached as Exhibit 99.1 hereto and is incorporated herein by reference.

The information in this Current Report on Form 8-K and the Exhibit attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, regardless of any general incorporation language in such filing.

The Company reports its financial results in accordance with GAAP. Additionally, the Company supplements reported GAAP financials with non-GAAP measures which are included in related press releases and reports furnished to the SEC, copies of which are available at the Company’s website: http://www.exar.com or the SEC’s website at: http://www.sec.gov. In this press release and in related comments by management, we are disclosing non-GAAP gross profit, non-GAAP operating expenses, non-GAAP operating income or loss, non-GAAP net income or loss, and non-GAAP basic and diluted net income or loss per share, which are adjusted to exclude from our GAAP results all stock-based compensation expense, amortization of acquired intangible assets, restructuring charges and exit costs, provision for dispute resolution, certain income tax credits, and related income tax effects on certain excluded items. We are also disclosing the non-GAAP measure of free cash flow, which is derived from our net cash provided (used) by operations, less purchases of fixed assets and IP, plus proceeds from the sale of IP. These non-GAAP measures are presented in part to enhance the understanding of the Company’s historical financial performance and comparability between reporting periods. The Company believes the non-GAAP presentation, when shown in conjunction with the corresponding GAAP measures, provides relevant and useful information to analysts, investors, management and other interested parties. For its internal purposes, the Company uses the foregoing non-GAAP measures to evaluate performance across reporting periods, determine certain employee benefits as well as plan for and forecast the Company’s future periods. These non-GAAP measures are not in accordance with, or an alternative for measures prepared in accordance with GAAP, and may be different from non-GAAP measures used by other companies. In addition, these non-GAAP measures are not based on any comprehensive set of accounting rules or principles. The Company believes that non-GAAP measures have limitations in that they do not reflect all of the amounts associated with the Company’s results of operations as determined in accordance with GAAP. These measures should only be used to evaluate the Company’s results of operations in conjunction with the corresponding GAAP measures.

A supplemental reconciliation of GAAP financial measures to non-GAAP financial measures is included in the financial statements portion of the press release attached as Exhibit 99.1 to this Current Report on Form 8-K.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.