FastResolver v1.26 - Scan IP addresses for host names and MAC addresses
Copyright (c) 2005 - 2014 Nir Sofer

Related Utilities

  • NetResView - View all computers/shares on your network.
  • PingInfoView - Ping to multiple host names/IP addresses.


FastResolver is a small utility that resolves multiple host names into IP addresses and vice versa. You can simply type the list of IP addresses or host name that you want to resolve, or alternatively, you can specify IP addresses range that you want to scan. For local network, FastResolver also allows you to get the MAC address of all IP addresses that you scan. FastResolver is a multithreaded application, so it can resolve dozens of addresses within a few seconds.

Versions History

  • Version 1.26:
    • Added 'Copy As Hosts File' option. (Ctrl+H)
  • Version 1.25:
    • Added 'MAC Address Format' option (XX-XX-XX-XX-XX-XX, XX:XX:XX:XX:XX:XX, or XXXXXXXXXXXX).
  • Version 1.23:
    • Fixed to work with the latest versions of oui.txt
  • Version 1.22:
    • Fixed bug: The size of addresses list text-box was limited to 32 KB.
  • Version 1.21:
    • Added support for typing IP range, like
  • Version 1.20:
    • Added 'Company Name' column that is determined according to the MAC address (Requires to download externl file - see below)
  • Version 1.16:
    • Fixed bug: The main window lost the focus when the user switched to another application and then returned back to FastResolver.
  • Version 1.15:
    • Added support for starting the IP addresses scanning from command-line
    • Added support for saving into comma-delimited (.csv) file.
    • Fixed bug in radio buttons of mode selection
  • Version 1.10:
    • Added support for scanning MAC addresses (works only for local network).
    • Added new option: Resolve hosts without domain.
    • The configuration is now saved to a file, instead of the Registry.
  • Version 1.00 - First release.

System Requirements

  • Windows operating system: Windows 98/ME/2000/XP/2003.
  • Network connection.

Be aware that resolving IP address to host name doesn't work well under Windows 98/ME.

Using FastResolver

FastResolver doesn't require any installation process or additional DLLs. Just put the executable file (FastResolver.exe) anywhere you like, and run it.
After you run FastResolver utility, you can type multiple IP addresses and host names, separated by commas, spaces, or CRLF. Alternatively, you can select IP addresses range to resolve into host names.

The 'Company Name' Column

Starting from version 1.20, FastResolver allows you to view the company name of each MAC address. However, in order to get this feature, you must download the following external file, and put in the same folder of FastResolver.exe:
Be aware that you must save it as 'oui.txt'

Options Menu

  • Display Multiple Host IP Addresses: If this option is checked, and the host name has multiple IP addresses, all IP addresses are displayed.
  • Resolve IP Addresses Back To Host Name: If this option is checked, and you resolve an host name to IP address, the IP Address is resolved back into a host name, and displayed in "Host Name" column. The original host name that you typed is displayed under "Original Name" column.

Command-Line Options

/IPFrom <IP Address> Specifies the from IP address
/IPTo <IP Address> Specifies the to IP address
/GetMACAddresses <0 | 1> Specifies whether you want to get the MAC addresses. 1 to enable, 0 to disable.
/DisplayMultiIPAddr <0 | 1> Display Multiple Host IP Addresses. 1 to enable, 0 to disable.
/ResolveIPAddrToHost <0 | 1> Resolve IP Addresses Back To Host Name. 1 to enable, 0 to disable.

FastResolver.exe /IPFrom /IPTo /GetMACAddresses 1

Translating FastResolver to other languages

FastResolver allows you to easily translate all menus, dialog-boxes, and other strings to other languages.
In order to do that, follow the instructions below:
  1. Run FastResolver with /savelangfile parameter:
    FastResolver.exe /savelangfile
    A file named FastResolver_lng.ini will be created in the folder of FastResolver utility.
  2. Open the created language file in Notepad or in any other text editor.
  3. Translate all menus, dialog-boxes, and string entries to the desired language. Optionally, you can also add your name and/or a link to your Web site. (TranslatorName and TranslatorURL values) If you add this information, it'll be used in the 'About' window.
  4. After you finish the translation, Run FastResolver, and all translated strings will be loaded from the language file.
    If you want to run FastResolver without the translation, simply rename the language file, or move it to another folder.


This utility is released as freeware. You are allowed to freely distribute this utility via floppy disk, CD-ROM, Internet, or in any other way, as long as you don't charge anything for this. If you distribute this utility, you must include all files in the distribution package, without any modification !


The software is provided "AS IS" without any warranty, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The author will not be liable for any special, incidental, consequential or indirect damages due to loss of data or any other reason.


If you have any problem, suggestion, comment, or you found a bug in my utility, you can send a message to
Download FastResolver (in ZIP file)
Download self-install executable for installing FastResolver with uninstall support

FastResolver is also available in other languages. In order to change the language of FastResolver, download the appropriate language zip file, extract the 'fastresolver_lng.ini', and put it in the same folder that you Installed FastResolver utility.

LanguageTranslated ByDateVersion
ArabicAbu Rehaam20/07/20231.26
Brazilian PortuguesePaulo Guzmán30/06/20121.22
Bulgarian Борислав Борисов - Voodoo23/01/20151.0
DutchJan Verheijen17/12/20141.26
Galician Xosé Antón Vicente Rodríguez12/10/2005 
German «Latino» auf WinTotal14/12/20141.26
Greek geogeo.gr03/07/20141.25
Italian Giacomo Margarito04/11/2005 
Japanese Nardog15/07/2006 
Japanese SABAdmin03/08/2008 
LatvianAndris Jansons09/01/20161.26
Polish wins04/10/2005 
Romanian Jaff (Oprea Nicolae)06/03/20141.25
RussianDmitry Yerokhin13/12/20141.26
Simplified Chineserenda27/07/2008 
Simplified Chinese 发梦 King25/07/2008 
Slovak Michal "KuboF" Matúšov07/09/20081.20
Slovenian Jadran Rudec28/11/2005 
Spanish arquer.net20/05/2009 
Traditional Chinese Wilson ko17/10/2005 
Traditional Chinese 發夢 King25/07/2008 
Thai ในฝัน.com Free Domain + Host18/11/20121.22
Turkish Cemil Kaynar23/10/20161.26
Valencian vjatv25/04/2008