Parse stack traces from JavaScript, Python, Java, and Go with clickable file paths and line highlighting.
A raw crash log becomes a per-frame breakdown here: file, line, column, and function for every frame, with paths rendered as links and the failing line called out. It recognizes Python, JavaScript (V8/Node), Java, and Go traceback shapes, so one paste works for server logs, CI output, and test failures. The surprise: it never sees your code. Parsing happens entirely on the pasted text, so 'clickable' paths are derived from the trace itself - the tool cannot verify the file exists or open your editor.
A concrete input and expected output from the current implementation.
Input
Traceback (most recent call last):
File "app.py", line 8, in <module>
main()
File "app.py", line 5, in main
process("data.csv")
File "app.py", line 2, in process
return int(value)
ValueError: invalid literal for int() with base 10: 'abc' Expected output
Renders an error banner - ValueError: invalid literal for int() with base 10: 'abc' - above three frames listed outermost first: app.py:8 in <module> (calls main()), app.py:5 in main (calls process("data.csv")), app.py:2 in process (line `return int(value)`, marked as the raised-at frame). Each path is a link and line numbers 8, 5, 2 are highlighted. Each `File "...", line N, in name` line becomes one frame, and the final line carries the exception type and message. The last frame is the deepest call, where int('abc') actually failed; the earlier frames are the call chain that led there.
The pasted text is scanned for known stack signatures: Python's `Traceback (most recent call last):` with `File "...", line N, in name` entries, Java's `at package.Class.method(File.java:N)` lines, Go's `goroutine N [running]:` blocks with `path/file.go:N` frames, and JavaScript's `at name (file.js:N:C)` lines. Each match becomes one frame; file, line, column, and function are extracted, and the leftover lines are grouped as the error message.
Frames keep their original order, outermost call first and the raised-at frame last, so the bottom of the list is where the exception actually fired. Each frame shows its path as a link and its line number highlighted. Everything is derived from the pasted text alone: nothing is uploaded, no source files are consulted, and a link cannot open a file the browser cannot see.
Java traces are usually pasted with the `Exception in thread "main"` header; without it, or when a logger wrapped the lines, the `at ...` frames may not match. Paste the complete, unmodified block, including the header and any `Caused by:` sections, and parse again. If it still comes back empty, the output format is one the parser does not recognize.
Neither. Parsing runs entirely in the browser on the text you paste, and nothing is uploaded. Paths and line numbers are extracted from the trace itself, which is why it works without your code present - and also why it cannot confirm that a path like app.py:8 exists or points at the current version of the file.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
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