QLogExplorer

QLogExplorer is a free, open-source log viewer and analyzer designed to inspect large log files without excessive memory consumption. It uses chunk indexing to support browsing and searching while files are still being processed. Its nonlocking file access allows other applications to rotate, move, or delete active logs. Users can convert unstructured text into organized columns using regular expressions with named capture groups. Native JSON and NDJSON support simplifies working with structured application logs. Advanced searches combine substring, regular expression, and range filters with AND, OR, and negation operators. Reusable templates preserve column layouts, highlighting rules, and predefined searches. Built with C++ and Qt, QLogExplorer is available for Windows and Linux.