What is the difference between JSONL and normal JSON?

JSONL, also called JSON Lines or NDJSON, stores one complete JSON value per line. Normal JSON is usually one object or array document, even if it spans many lines.

Can I validate private logs here?

Yes. Validation happens in your browser, so pasted log records are not uploaded, stored, or sent to a server.

Does this validate each row against JSON Schema?

No. It parses each line and checks basic top-level key consistency. Use the JSON Schema Validator for a single JSON document and schema contract checks.

Why does pretty-printed JSON fail as JSONL?

JSONL expects every line to be a full JSON value. A pretty-printed object spans multiple lines, so individual lines like braces or partial fields are not valid records by themselves.

format validator

JSONL Validator & NDJSON Checker

Validate JSON Lines and NDJSON records locally with line-precise parsing errors and basic key consistency checks.

Results

Paste input and validate locally.

Status: Ready when you validate.
Details: Ready when you validate.
Total lines: Ready when you validate.
Records parsed: Ready when you validate.

Rules & checks

Parses each non-empty line as an independent JSON value.

Reports the exact line number when a row contains invalid JSON syntax.

Checks basic top-level object key consistency across records so accidental field drift is easier to spot.

Works for JSON Lines, NDJSON, log streams, queue exports, and batch import files.

Runs entirely in your browser; pasted data is not uploaded, logged, or stored.

When to use it

Preflight JSONL files before loading them into analytics, BI, or warehouse tools.
Validate NDJSON API exports before replaying them through scripts or queues.
Check event streams, audit logs, webhook batches, and queue dead-letter records for malformed rows.
Clean user-provided newline-delimited JSON uploads in support or data migration workflows.
Verify fixture files used by tests, seed scripts, and local development tools.

Common errors

Pasting a normal JSON array instead of one JSON object per line.
Leaving trailing commas at the end of JSONL records.
Splitting one pretty-printed JSON object across multiple lines.
Mixing field names such as user_id, userId, and id in the same import.
Including comments, headers, or non-JSON log prefixes before the JSON payload.

Limitations

This checks JSON syntax and basic key consistency; it does not apply a formal JSON Schema to every line.
It does not fetch remote schema files, sample URLs, or external references.
Large pasted files may be constrained by your browser memory and textarea performance.
Pretty-printed multi-line JSON is not JSONL; each line must be a complete JSON value.

Tips

Keep each record on a single line; use the JSON Prettifier only after isolating one row.
If your data is wrapped in square brackets, validate it with the JSON Validator first, then export it as JSONL if your import tool requires one record per line.
Use consistent top-level keys across records when loading into typed tables or analytics schemas.
Validate sensitive logs locally here, then redact secrets before sharing snippets with teammates.
For size-sensitive payloads, validate JSONL first and use the JSON Minifier for individual JSON objects or arrays.

Examples

Valid JSON Lines event export

{"event":"signup","userId":101,"plan":"pro"}
{"event":"purchase","userId":101,"amount":49}
Each line is parsed as its own JSON record.

Bad line in an NDJSON import

{"id":1,"name":"Ada"}
{"id":2,"name":"Grace",}
The trailing comma is flagged on line 2 instead of making you debug the whole file.

Field drift across records

{"id":1,"email":"ada@example.com"}
{"id":2,"fullEmail":"grace@example.com"}
A changed top-level key is reported so you can fix the export before loading it.

FAQs

What is the difference between JSONL and normal JSON?: JSONL, also called JSON Lines or NDJSON, stores one complete JSON value per line. Normal JSON is usually one object or array document, even if it spans many lines.
Can I validate private logs here?: Yes. Validation happens in your browser, so pasted log records are not uploaded, stored, or sent to a server.
Does this validate each row against JSON Schema?: No. It parses each line and checks basic top-level key consistency. Use the JSON Schema Validator for a single JSON document and schema contract checks.
Why does pretty-printed JSON fail as JSONL?: JSONL expects every line to be a full JSON value. A pretty-printed object spans multiple lines, so individual lines like braces or partial fields are not valid records by themselves.

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Minify JSON locally into compact, whitespace-free output for curl commands, environment variables, webhooks, signed requests, and config values.

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JSON Diff Checker

Compare two JSON payloads locally to spot added, removed, or changed fields before API, webhook, or config changes ship.

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JSON Schema Validator

Validate JSON Schema contracts with AJV, then test sample request or response JSON locally before you ship an API change.

All JSONL/NDJSON validation runs locally in your browser. Your records, logs, customer data, and API payloads are not uploaded, logged, or stored.

JSONL syntax and basic record-shape validation only; this tool does not enforce external schemas, business rules, or destination-specific import requirements.