Click the "Select File" button above, and choose your 12M file.
You’ll see a preview, if available.
Click the "Convert file to..." button to extract text information.
Convert 12M to another file type
To convert 12M SmartMaster files to another format, you need Lotus 1-2-3 or other Spreadsheet software.
Convert a file to 12M
To convert other file formats to the "Legacy Spreadsheet Template" file type, you need software like Lotus 1-2-3 or a similar tool.
About 12M files
The .12M file is a SmartMaster template created by Lotus 1-2-3, a historic spreadsheet program developed by IBM. It stores pre-formatted spreadsheet layouts, macros, and financial formulas used to generate standard 123 files. Historically, these files were managed using Lotus SmartSuite on older Windows operating systems. Because IBM officially ended all support in 2014, the .12M format is essentially obsolete. It is a closed, proprietary format that modern applications like Microsoft Excel or Google Sheets do not support natively. Users are often locked out of their legacy financial data unless they maintain a 32-bit virtual machine. It is critical to convert .12M files to modern formats like XLSX or CSV for active data manipulation, or PDF for static visual archiving. Be aware that complex Lotus macros and proprietary formatting will likely be lost during the transition. This file format is notoriously difficult to open or convert because standard online converters lack the legacy parsing engines required to decode the proprietary binary structure. Often, only the original software can properly read or export the data. If our analysis detects a supported underlying or embedded format, viewing or conversion may still be possible.
Convert.Guru analyzes your 12M file, detects the exact format, and lets you read the text inside.
If you want to convert 12M file to KM, XLS, XLSX, XLSM, XLSB, ODS, CSV, TSV, TAB, DIF, SLK or WK1, you can use Lotus 1-2-3 or similar software from the "Spreadsheet Template Storage" category. In the File menu, look for Save As… or Export….
To convert WQ1, XLSM, NOTES, QPW, WK3, WB2, WKS, XLSB, 123, XLS, WB1 or XLSX files to 12M, try Lotus 1-2-3 or another comparable tool in the "Spreadsheet Template Storage" category.
The 12M Converter Story
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our 12M converter.