What is the PMA file format?
A .pma file is a binary alert log produced by Windows Performance Monitor (perfmon.exe), a built-in Windows tool for tracking system metrics such as CPU load, memory consumption, disk throughput, and network activity. The .pma format records alert events - timestamped entries written whenever a monitored counter crosses a user-defined threshold.
Performance Monitor uses a family of five file types to capture different aspects of monitoring data. The .pma file handles alert logs specifically; companion formats include .pmc (counter settings), .pml (continuous log data), .pmr (report snapshots), and .pmw (workspace configuration). All five share a proprietary Microsoft binary structure and have been part of Windows since NT 3.1 (1993).
The format is produced when a user configures a counter alert in Performance Monitor and lets it run - for example, triggering an alert whenever CPU usage exceeds 90%. The resulting .pma file can be reopened in Performance Monitor on any compatible Windows machine.
Modern Windows (Vista onward) migrated Performance Monitor to the .blg (binary log) format for general logging, and Event Tracing for Windows (.etl) for high-resolution diagnostics. Legacy .pma files can still be opened in current Performance Monitor, but new installations produce .blg or .csv output by default. Users may also encounter .pma files inside Chromium-based browser profile folders (Chrome, Edge), where the browser engine uses the extension for internal performance telemetry unrelated to Windows Perfmon.
Security & safety
RISK: LOWBinary data files that cannot execute code. Deleting .pma files from browser profile folders (Chrome/Edge) is safe - the browser recreates them. Perfmon alert logs from unknown sources pose no execution risk, but may contain sensitive system performance or hostname data.
Format details
in a nutshell- phpMyAdmin Compiled Template - phpMyAdmin pre-compiles Smarty PHP templates to .pma files for caching; completely unrelated to Windows Perfmon.
Programs that open PMA files
Windows2 apps
Windows Performance Monitor
Built-in Run perfmon.exe, go to Performance Monitor > Action > Open > browse to the .pma file. 
Microsoft Excel (via CSV export)
Paid Export from Perfmon to .csv first (File > Export), then open in Excel. Technical details
deep spec| File purpose | Records timestamped alert events from Windows Performance Monitor when counters cross user-defined thresholds |
| Encoding | Binary (proprietary Microsoft Perfmon log format) |
| Byte order | Little-endian |
| Magic bytes | 04 00 00 00 at offset 0 |
| Related Perfmon formats | .pmc (counter settings), .pml (log data), .pmr (report), .pmw (workspace) - five-format Perfmon family |
| Introduced | Windows NT 3.1 (1993) with the original Performance Monitor tool |
| Superseded by | .blg (binary log) for general logging; .etl (Event Tracing for Windows) for high-resolution diagnostics |
| Platform | Windows NT, 2000, XP, Vista, 7, 8, 10, 11 |
| Typical file size | 1 KB - 50 MB depending on monitoring duration and counter count |
| Secondary occurrence | Chromium-based browsers (Chrome, Edge) write .pma files in profile folders for internal performance telemetry, unrelated to Perfmon |
| Readable with | Windows Performance Monitor (perfmon.exe); data can be exported to CSV for analysis in Excel |
| Format visibility | Proprietary Microsoft binary format; no public specification published |
| Released | Windows NT 3.1, 1993 |
| Latest version | N/A (format unchanged through current Windows) |
| Specification | docs.microsoft.com |
PMA conversions
Community Q&A
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