analyze-to-ndjson

Converts Next.js bundle analyzer binary .data files into grep/jq-friendly NDJSON.

Generate the data

pnpm next experimental-analyze --output

This writes binary files to .next/diagnostics/analyze/data/.

Run the converter

node tools/analyze-to-ndjson.mjs

Options:

• --input <dir> — source directory (default: .next/diagnostics/analyze/data)
• --output <dir> — output directory (default: ./analyze-ndjson)

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

# All routes sorted by compressed size
jq -s 'sort_by(-.total_compressed_size)' analyze-ndjson/routes.ndjson

Find large sources

# Top 10 largest sources (deduplicated by full_path)
jq -s '
  group_by(.full_path)
  | map(max_by(.compressed_size))
  | sort_by(-.compressed_size)
  | .[0:10]
  | .[] | {full_path, compressed_size, size, route}
' analyze-ndjson/sources.ndjson

Client-side JS

# Largest client JS sources
grep '"client":true' analyze-ndjson/sources.ndjson \
  | grep '"js":true' \
  | jq -s 'sort_by(-.compressed_size) | .[0:10] | .[] | {full_path, compressed_size}'

Module dependencies

# What does module 42 depend on?
grep '"from":42,' analyze-ndjson/module_edges.ndjson | jq .to

# Who depends on module 42?
grep '"to":42,' analyze-ndjson/module_edges.ndjson | jq .from

# Look up a module by path fragment
grep 'react-dom' analyze-ndjson/modules.ndjson | jq '{id, path}'

Output files for a route

# Largest output files for the "/" route
grep '"route":"/"' 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

# Top-level directories for "/"
grep '"route":"/"' analyze-ndjson/sources.ndjson \
  | jq 'select(.parent_id == null)'

Feeding to an LLM

The NDJSON files are self-contained — each line has all the context needed to understand it. You can pass a whole file or a filtered subset as context:

# Give an LLM the route summary + the top 20 client sources
cat analyze-ndjson/routes.ndjson > /tmp/context.ndjson
grep '"client":true' analyze-ndjson/sources.ndjson \
  | jq -s 'sort_by(-.compressed_size) | .[0:20] | .[]' -c \
  >> /tmp/context.ndjson