Why count JSON lines instead of just object count?
Because JSONL workflows care about physical lines, blank-line policy, and approximate batch size during imports.
JSON Line Counter
Count JSONL records and detect invalid rows quickly
JSON & Data
π 100% client-side β your data never leaves this pagePage mode
JSONL Input
Quick CTA
Paste JSONL and inspect the line count plus invalid rows first; strict validation and preview settings stay in Deep.
Output
Analysis result appears here
100% client-side
Next step workflow
Page reading mode
Quick keeps the summary, direct answers, and next steps so you can validate fit and get a result faster.
About this tool
JSON Line Counter is built for JSONL/NDJSON sanity checks before data import. Paste your line-delimited JSON data to count total rows, non-empty records, valid/invalid JSON lines, and byte-size distribution. The tool highlights invalid lines with line numbers so you can fix broken records before running ETL, ingestion, or log analytics pipelines. You can switch validation off when you only need quick counting. It is useful for data migration readiness, QA of generated logs, and preflight checks for bulk upload jobs. All analysis happens in your browser; no dataset is sent out.
Direct Answers
Do blank lines matter?
Yes. Some pipelines ignore them while others fail hard, so counting strategy changes the operational meaning.