Vercel Labs analyze-to-ndjson
Converts Next.js bundle analyzer binary .data files into grep/jq-friendly NDJSON.
Analyze artifacts
This workflow pre-generates analyzer artifacts in:
.next/diagnostics/analyze/ndjson/routes.ndjson.next/diagnostics/analyze/ndjson/sources.ndjson.next/diagnostics/analyze/ndjson/output_files.ndjson.next/diagnostics/analyze/ndjson/module_edges.ndjson.next/diagnostics/analyze/ndjson/modules.ndjson
Focus on reading these files and using their evidence to prioritize changes.
Output files
| File | What's in it |
|---|---|
modules.ndjson |
Global module registry (id, ident, path) |
module_edges.ndjson |
Module dependency graph (from, to, kind: sync/async) |
sources.ndjson |
Per-route source tree with sizes and environment flags |
chunk_parts.ndjson |
Granular size data: one line per (source, output_file) pair |
output_files.ndjson |
Per-route output files with aggregated sizes |
routes.ndjson |
Route-level summaries |
Browsing the output
Route overview
jq -s 'sort_by(-.total_compressed_size)' .next/diagnostics/analyze/ndjson/routes.ndjson
Find large sources
jq -s '
group_by(.full_path)
| map(max_by(.compressed_size))
| sort_by(-.compressed_size)
| .[0:10]
| .[] | {full_path, compressed_size, size, route}
' .next/diagnostics/analyze/ndjson/sources.ndjson
Client-side JS
grep '"client":true' .next/diagnostics/analyze/ndjson/sources.ndjson \
| grep '"js":true' \
| jq -s 'sort_by(-.compressed_size) | .[0:10] | .[] | {full_path, compressed_size}'
Module dependencies
grep '"from":42,' .next/diagnostics/analyze/ndjson/module_edges.ndjson | jq .to
grep '"to":42,' .next/diagnostics/analyze/ndjson/module_edges.ndjson | jq .from
grep 'react-dom' .next/diagnostics/analyze/ndjson/modules.ndjson | jq '{id, path}'
Output files for a route
grep '"route":"/"' .next/diagnostics/analyze/ndjson/output_files.ndjson \
| jq -s 'sort_by(-.total_compressed_size) | .[0:10] | .[] | {filename, total_compressed_size, num_parts}'
Directory tree for a route
grep '"route":"/"' .next/diagnostics/analyze/ndjson/sources.ndjson \
| jq 'select(.parent_id == null)'