NDJSON Schema Consistency Checker

Scan NDJSON records for field drift, missing keys, invalid lines, and mixed value types.

Also useful for: ndjson schema checker jsonl schema checker ndjson field drift json lines consistency checker NDJSON Schema Consistency Checker

NDJSON Schema Consistency Checker

Runs in your browser. Inputs are not uploaded.
Input
Results
Summary: 3 NDJSON records checked. 1 warning, 3 notes.

Stats
- Records: 3
- Fields: 4

Issues
- Warning: id has multiple types: number, string.
- Note: email is missing from 1 record.
- Note: active is missing from 1 record.
- Note: name is missing from 2 records.

Output
id: number (2), string (1)
email: string (2)
active: boolean (2)
name: string (1)

NDJSON Schema Consistency Checker Example Run

Find field drift in line-delimited event data.

Sample inputs
{"id":1,"email":"ada@example.com","active":true}
{"id":"2","email":"grace@example.com"}
{"id":3,"name":"Lin","active":false}

Generated result
Summary: 3 NDJSON records checked. 1 warning, 3 notes.

Stats
- Records: 3
- Fields: 4

Issues
- Warning: id has multiple types: number, string.
- Note: email is missing from 1 record.
- Note: active is missing from 1 record.
- Note: name is missing from 2 records.

Output
id: number (2), string (1)
email: string (2)
active: boolean (2)
name: string (1)

What the NDJSON Schema Consistency Checker Checks

  • One object per line

    Each non-empty line must parse as a JSON object.

  • Field inventory

    All keys seen across records are collected into an inferred schema summary.

  • Type drift

    Fields with more than one observed value type are reported as warnings.

  • Missing fields

    Fields absent from some records are reported so optional versus accidental gaps are visible.

  • Streaming-friendly input

    The checker works on pasted NDJSON or JSONL without wrapping records in an array.

NDJSON Schema Consistency Checker Questions

  • Q: Does the NDJSON schema consistency checker upload my NDJSON? A: No. Inputs are processed in your browser, and pasted content is not sent to analytics or a server.
  • Q: What should I paste into the NDJSON schema consistency checker? A: Paste one JSON object per line from logs, events, exports, or JSONL datasets.
  • Q: What can I copy or download? A: You can copy the inferred field/type report.
  • Q: What does the NDJSON schema consistency checker not verify? A: It does not infer a formal JSON Schema, validate business rules, or sample files larger than the browser can comfortably process.

Use NDJSON Schema Consistency Checker with an LLM

Copy the prompt or pass the llms.txt contract link to your assistant.

Prompt
Use the CleanUtils NDJSON Schema Consistency Checker tool for this request.
Tool contract: https://cleanutils.com/developer-tools/ndjson-schema-consistency-checker/llms.txt

Read the llms.txt contract, ask me for any missing required input, then follow the contract exactly. If the contract includes JavaScript, run `runCleanUtilsTool(userInput)` in a sandboxed JavaScript runtime and return the result with any warnings or errors.