EXHIBIT 32.1

                            CERTIFICATION PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
                            (18 U.S.C. SECTION 1350)

      I, Robert Glaser, Chairman and Chief Executive Officer of RealNetworks,
Inc., certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of
RealNetworks, Inc. on Form 10-Q for the fiscal quarter ended March 31, 2005
fully complies with the requirements of Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 and that information contained in such Quarterly Report on
Form 10-Q fairly presents in all material respects the financial condition and
results of operations of RealNetworks, Inc.

Date:  May 6, 2005

                                     By: /s/ Robert Glaser
                                         ---------------------------------------
                                         Name:  Robert Glaser
                                         Title: Chairman and Chief Executive
                                                Officer (Principal Executive
                                                Officer)

A signed original of this written statement required by Section 906 has been
provided to RealNetworks, Inc. and will be retained by RealNetworks, Inc. and
furnished to the Securities and Exchange Commission or its staff upon request.