Stack trace formatter
Clean up and re-indent a pasted stack trace so the frames that matter stand out.
Stack trace formatter
Paste a raw stack trace — copied from a terminal, a log aggregator, or a crash report — and this tool re-indents it so the frames that actually matter are easy to find. It works with Java, JavaScript and Node.js, Python, C#, Go and Ruby traces, and can auto-detect which convention it's looking at from the frame shapes alone, no language picker required.
Turn on Collapse vendor frames to fold consecutive framework and library frames — anything under node_modules, java.base, site-packages and similar paths — into a single line, or switch on Keep only my frames to drop them entirely. Your source path lets you name the folders or packages that are actually yours, such as src/ or com/myapp, overriding the built-in vendor list. Number frames adds a running count, Shorten class names trims a fully qualified class down to its last two segments, and Show summary line prints the exception type, its message and the first frame in your own code above the reformatted trace.
A trace that arrived mangled onto a single line — pasted from a JSON log field with literal \n escapes instead of real line breaks — is unwrapped automatically before formatting, and a chain of "Caused by" exceptions is rendered as an indented tree instead of a flat wall of text. Windows and Unix line endings are both handled, and the tally under the output reports how many frames went in, how many are shown and how many were folded away.
Formatting happens entirely in your browser — the trace never leaves your device, which matters when it might contain internal file paths or class names. Copy the cleaned-up result, download it as a .txt file, or send it straight back into the input to adjust the options and reformat again.