.123 File Extension

Learn about .123 files and view a list of programs that open them.

Lotus 1-2-3 was first developed by Lotus Development Corporation, which was bought by IBM in 1995 and integrated into part of IBM Lotus SmartSuite. The "1-2-3" refers to the program's three main capabilities: 1) spreadsheet functions, 2) creating charts and graphs, and 3) basic database operations.

The 123 file format is a proprietary format introduced with the release of the 97 Edition of Lotus 1-2-3 in 1997. The format replaced the .WK4 format introduced with version 4 of Lotus 1-2-3.

Lotus 1-2-3 was first developed by Lotus Development Corporation, which was bought by IBM in 1995 and integrated into part of IBM Lotus SmartSuite. The "1-2-3" refers to the program's three main capabilities: 1) spreadsheet functions, 2) creating charts and graphs, and 3) basic database operations.

The 123 file format is a proprietary format introduced with the release of the 97 Edition of Lotus 1-2-3 in 1997. The format replaced the .WK4 format introduced with version 4 of Lotus 1-2-3.

You can open 123 files with Lotus 1-2-3, but IBM no longer develops the software. Other third-party applications that support 123 files include Corel Quattro Pro (Windows), OpenOffice Calc (multiplatform), Planamesa NeoOffice (macOS), and Gnumeric (Linux).