<PAGE>
 
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                      SECURITIES AND EXCHANGE COMMISSION
 
                            Washington, D.C. 20549
 
                                ---------------
 
                                  FORM 10-K/A
 
                       FOR ANNUAL AND TRANSITION REPORTS
                    PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934
 
[X]ANNUAL REPORT PURSUANT TO SECTION l3 OR l5(d) OF THE SECURITIES EXCHANGE
   ACT OF l934
 
                  For the fiscal year ended December 31, 1998
 
                                      OR
 
[_]TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
   EXCHANGE ACT OF 1934
 
                        Commission file number 0-25107
 
                                 EarthWeb Inc.
 
            (Exact name of registrant as specified in its charter)
 
<TABLE>
<CAPTION>
                 Delaware                              13-3899472
      <S>                                 <C>
      (State or other jurisdiction of     (I.R.S. Employer Identification No.)
      incorporation or organization)
</TABLE>
 
                    3 Park Avenue, New York, New York 10016
         (Address of principal executive offices, including zip code)
 
      Registrant's telephone number, including area code: (212) 725-6550
 
       Securities registered pursuant to Section 12(b) of the Act: None
 
          Securities registered pursuant to Section l2(g) of the Act:
                    Common Stock, par value $.01 per share
                               (Title of class)
 
                                ---------------
 
  Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section l3 or l5(d) of the Securities Exchange Act of
l934 during the preceding l2 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to
such filing requirements for the past 90 days.  Yes [X]  No [_]
 
  Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to
the best of registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. [ ]
 
  The aggregate market value of voting stock held by nonaffiliates of the
registrant, based on the closing price of the common stock on March 1, 1999 of
$37.75, as reported on the NASDAQ National Market was approximately
$158,228,219. Shares of common stock held by each officer and director and by
each person who owns 5% or more of the outstanding common stock have been
excluded in that such persons may be deemed to be affiliates. This
determination of affiliate status is not necessarily a conclusive
determination for any other purpose.
 
  As of March 1, 1999, the registrant had outstanding 8,509,862 shares of
common stock, $.01 par value.
 
                     DOCUMENTS INCORPORATED BY REFERENCE:
 
  The following documents (or parts thereof) are incorporated by reference
into the following parts of this Form 10-K:
 
(1) 1998 Annual Report to Stockholders--Items 5, 6, 7, 8 and 14(a). With the
    exception of those portions that are incorporated by reference, the
    Registrant's 1998 Annual Report is not deemed filed as part of this
    Report.
 
(2) Proxy Statement for the 1999 Annual Meeting of Stockholders--Items 10, 11,
    12 and 13.
 
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This 10-K/A is being filed to amend Item 14, to amend Exhibit 13.1 to replace
pages 10, 17, 22, 27 and 30 of Exhibit 13.1 with amended pages, and to amend 
Exhibit 27.



<PAGE>
 
                                    PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

a) Documents filed as part of this Report:
   --------------------------------------

The following financial statements and the Report of the Independent Accountants
are incorporated herein by reference to the Registrant's 1998 Annual Report to 
Stockholders pursuant to Item 8:
 
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                                                                               Page
                                                                             -------
<S>                                                                          <C>
Balance Sheets at December 31, 1998 and 1997...............................     16
Statement of Operations for the years ended December 31, 1998, 1997 and         
 1996......................................................................     17
                                                                                
Statements of Stockholders' Equity for the years ended December 31, 1998,       
 1997 and 1996.............................................................     18
                                                                                
Statements of Cash Flows for the years ended December 31, 1998, 1997 and        
 1996......................................................................     19
                                                                                
Notes to Financial Statements..............................................    20-28
Report of Independent Accountants..........................................     29
</TABLE>

All other financial statement schedules are omitted because they are not
required, are inapplicable or the information has been included elsewhere in the
financial statements or notes thereto.

b)    Reports on Form 8-K.
      -------------------
No Reports on Form 8-K were filed during the fourth quarter of 1998.  A Report 
on Form 8-K was filed on each of February 16, 1999 and March 26, 1999. A Report 
on Form 8-K/A was filed on April 15, 1999.

c)  Exhibits.
    -------- 

<TABLE>
<CAPTION>
     Exhibit No.       Description
---------------------  -----------
<C>                    <S>
       *2.1            Agreement and Plan of Merger among Registrant, EW Career Solutions, Inc., D&L Online, Inc., Lloyd
                       Linn, and Diane Rickert; incorporated by reference to Exhibit 2.1 to the Registrant's Current Report
                       on Form 8-K dated February 2, 1999.
        3.1            Form of Amended and Restated Certificate of Incorporation; incorporated by reference to Exhibit 3.1
                       to Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
        3.2            Form of Amended and Restated By-laws; incorporated by reference to Exhibit 3.2 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.1            Amended and Restated Shareholders Agreement dated as of June 24, 1997 among the Registrant, EarthWeb
                       LLC, Global Network Partners LLC ("GNP"), Warburg, Pincus Ventures, L.P. ("Warburg"), Jack D. Hidary,
                       Murray Hidary and Nova Spivack; incorporated by reference to Exhibit 4.1 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.2            Specimen Common Stock Certificate of Registrant; incorporated by reference to Exhibit 4.2 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.3            Registration Rights Agreement dated as of October 25, 1996 by and between the Registrant, Warburg,
                       EarthWeb LLC and GNP; incorporated by reference to Exhibit 4.3 to Registrant's Registration
                       Statement on Form S-1 (SEC File No. 333-60837).
        4.4            Registration Rights Agreement between Registrant, Lloyd Linn and Diane Rickert; incorporated by
                       reference to Exhibit 4.1 to the Registrant's Current Report on Form 8-K dated February 2, 1999.
          9            Form of Voting Trust Agreement, as amended; incorporated by reference to Exhibit 9 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
       10.1            1996 Amended and Restated Stock Plan, as amended; incorporated by reference to Exhibit 10.1 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
       10.2            Employment Agreement dated January 1, 1995 between GNP (formerly EarthWeb Ltd.) and Jack D. Hidary;
                       incorporated by reference to Exhibit 10.2 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
</TABLE> 



<PAGE>
 
<TABLE> 
<CAPTION>
     Exhibit No.       Description
---------------------  -----------
<S>                    <C> 
       10.3            Employment Agreement dated January 1, 1995 between GNP (formerly EarthWeb Ltd.) and Murray Hidary;
                       incorporated by reference to Exhibit 10.3 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
       10.4            Employment Agreement dated November 4, 1996 between the Registrant and Irene Math; incorporated by
                       reference to Exhibit 10.4 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.5            Employment Agreement dated November 3, 1997 between the Registrant and William Gollan; incorporated
                       by reference to Exhibit 10.5 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.6            Employment Agreement dated January 12, 1998 between the Registrant and John Kleine; incorporated by
                       reference to Exhibit 10.6 to the Registrant's Annual Report on Form 10-K dated March 19, 1999.
       10.7            Consulting Agreement dated as of August 1, 1998 between the Registrant and Nova Spivack;
                       incorporated by reference to Exhibit 10.6 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
       10.8            Intercompany Services Agreement dated October 25, 1996 among the Registrant, EarthWeb LLC, GNP
                       (formerly EarthWeb Ltd.), Jack D. Hidary, Murray Hidary and Nova Spivack, as amended; incorporated
                       by reference to Exhibit 10.7 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.9            Lease Agreement dated April 28, 1995 between 3 Park Avenue Co. and MJN Enterprises, Inc., as
                       amended; incorporated by reference to Exhibit 10.8  to Registrant's Registration Statement on Form
                       S-1 (SEC File No. 333-60837).
      10.10            Form of 1998 Stock Incentive Plan; incorporated by reference to Exhibit 10.9 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
      10.11            Form of 1998 Employee Stock Purchase Plan; incorporated by reference to Exhibit 10.10 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
      10.12            Employment Agreement between Registrant and Lloyd Linn; incorporated by reference to Exhibit 10.1 to
                       the Registrant's Current Report on Form 8-K dated February 2, 1999.
       13.1            Amended pages of 1998 Annual Report to Stockholders; portions of the 1998 Annual Report to Stockholders are 
                       incorporated by reference herein.
       21.1            Subsidiary of Registrant; incorporated by reference to Exhibit 21.1 to the Registrant's Annual Report on Form
                       10-K dated March 19, 1999.
       23.1            Consent of Independent Accountants.
         27            Financial Data Schedule; incorporated by reference to Exhibit 27 to Registrant's Annual Report on Form 10-K 
                       dated March 19, 1999.
</TABLE>

     * Confidential treatment has been granted with respect to certain
       portions of this Exhibit.  Omitted portions have been filed separately 
       with the Commission.



<PAGE>
 
                                  SIGNATURES
 
  Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed
on its behalf by the undersigned, thereunto duly authorized, in the City of
New York, State of New York, on April 15, 1999.
 
                                          Earthweb Inc.
 
                                          By: /s/ Jack D. Hidary
                                              ---------------------------------
                                           Jack D. Hidary 

                                           President and
                                           Chief Executive Officer
<PAGE>
 
                                 EXHIBIT INDEX
 
c)  Exhibits.
    -------- 

<TABLE>
<CAPTION>
     Exhibit No.       Description
---------------------  -----------
<C>                    <S>
       *2.1            Agreement and Plan of Merger among Registrant, EW Career Solutions, Inc., D&L Online, Inc., Lloyd
                       Linn, and Diane Rickert; incorporated by reference to Exhibit 2.1 to the Registrant's Current Report
                       on Form 8-K dated February 2, 1999.
        3.1            Form of Amended and Restated Certificate of Incorporation; incorporated by reference to Exhibit 3.1
                       to Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
        3.2            Form of Amended and Restated By-laws; incorporated by reference to Exhibit 3.2 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.1            Amended and Restated Shareholders Agreement dated as of June 24, 1997 among the Registrant, EarthWeb
                       LLC, Global Network Partners LLC ("GNP"), Warburg, Pincus Ventures, L.P. ("Warburg"), Jack D. Hidary,
                       Murray Hidary and Nova Spivack; incorporated by reference to Exhibit 4.1 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.2            Specimen Common Stock Certificate of Registrant; incorporated by reference to Exhibit 4.2 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
        4.3            Registration Rights Agreement dated as of October 25, 1996 by and between the Registrant, Warburg,
                       EarthWeb LLC and GNP; incorporated by reference to Exhibit 4.3 to Registrant's Registration
                       Statement on Form S-1 (SEC File No. 333-60837).
        4.4            Registration Rights Agreement between Registrant, Lloyd Linn and Diane Rickert; incorporated by
                       reference to Exhibit 4.1 to the Registrant's Current Report on Form 8-K dated February 2, 1999.
          9            Form of Voting Trust Agreement, as amended; incorporated by reference to Exhibit 9 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
       10.1            1996 Amended and Restated Stock Plan, as amended; incorporated by reference to Exhibit 10.1 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
       10.2            Employment Agreement dated January 1, 1995 between GNP (formerly EarthWeb Ltd.) and Jack D. Hidary;
                       incorporated by reference to Exhibit 10.2 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
       10.3            Employment Agreement dated January 1, 1995 between GNP (formerly EarthWeb Ltd.) and Murray Hidary;
                       incorporated by reference to Exhibit 10.3 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
       10.4            Employment Agreement dated November 4, 1996 between the Registrant and Irene Math; incorporated by
                       reference to Exhibit 10.4 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.5            Employment Agreement dated November 3, 1997 between the Registrant and William Gollan; incorporated
                       by reference to Exhibit 10.5 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.6            Employment Agreement dated January 12, 1998 between the Registrant and John Kleine; incorporated by
                       reference to Exhibit 10.6 to the Registrant's Annual Report on Form 10-K dated March 19, 1999.
       10.7            Consulting Agreement dated as of August 1, 1998 between the Registrant and Nova Spivack;
                       incorporated by reference to Exhibit 10.6 to Registrant's Registration Statement on Form S-1 (SEC
                       File No. 333-60837).
       10.8            Intercompany Services Agreement dated October 25, 1996 among the Registrant, EarthWeb LLC, GNP
                       (formerly EarthWeb Ltd.), Jack D. Hidary, Murray Hidary and Nova Spivack, as amended; incorporated
                       by reference to Exhibit 10.7 to Registrant's Registration Statement on Form S-1 (SEC File No.
                       333-60837).
       10.9            Lease Agreement dated April 28, 1995 between 3 Park Avenue Co. and MJN Enterprises, Inc., as
                       amended; incorporated by reference to Exhibit 10.8  to Registrant's Registration Statement on Form
                       S-1 (SEC File No. 333-60837).
      10.10            Form of 1998 Stock Incentive Plan; incorporated by reference to Exhibit 10.9 to Registrant's
                       Registration Statement on Form S-1 (SEC File No. 333-60837).
      10.11            Form of 1998 Employee Stock Purchase Plan; incorporated by reference to Exhibit 10.10 to
                       Registrant's Registration Statement on Form S-1 (SEC File No. 333-60837).
      10.12            Employment Agreement between Registrant and Lloyd Linn; incorporated by reference to Exhibit 10.1 to
                       the Registrant's Current Report on Form 8-K dated February 2, [copy missing].
       13.1            Amended pages of 1998 Annual Report to Stockholders; portions of the 1998 Annual Report to Stockholders are 
                       incorporated by reference herein.
       21.1            Subsidiary of Registrant; incorporated by reference to Exhibit 21.1 to the Registrant's Annual Report on Form
                       10-K dated March 19, 1999.
       23.1            Consent of Independent Accountants.
         27            Financial Data Schedule; 
</TABLE>

     * Confidential treatment has been granted with respect to certain
       portions of this Exhibit.  Omitted portions have been filed separately 
       with the Commission.