Massive Log File Parser
Parse Apex debug logs and large .txt files (50MB+) without freezing the UI. Chunked Web Worker parsing with virtualized rendering.
Drop a .log or .txt file here, or click to browse
Optimized for Salesforce Apex execution logs and general debug output
Load a log file to begin
No file loaded
How This Tool Works
Files are read on the main thread in 2 MB slices via File.slice() and FileReader, then streamed to a dedicated Web Worker. The worker buffers partial lines across chunk boundaries, classifies each line (limit exceptions, fatal errors, SOQL timing, callouts), and returns structured results. The viewport uses DOM virtualization — only rows near the scroll position exist in the document, so 100,000+ lines render smoothly.
Key Benefits
- Zero server upload: Sensitive Apex logs and production debug traces never leave your machine.
- Apex-aware highlighting: Limit exceptions in red, slow SOQL (>100ms) in yellow, callouts in purple.
- Non-blocking UI: Parsing runs off the main thread so the browser stays responsive on 50MB+ files.
Practical Use Cases
- Salesforce developers: Quickly find governor limit failures and expensive SOQL in debug logs after a failed transaction.
- Integration debugging: Filter to callout lines when tracing HTTP request/response issues in Apex.
- Large log review: Search and scroll through server debug dumps without opening a desktop editor.
Frequently Asked Questions
What is the maximum file size?
There is no hard limit — performance depends on available RAM. Files up to 50MB+ are supported; very large files may take longer to parse but the UI remains interactive.
Does this work with non-Salesforce logs?
Yes. Generic error and exception highlighting applies to any text log. SOQL-specific detection targets Salesforce debug log patterns.