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Convert JSONL to JSON Online

Convert line-delimited JSONL or NDJSON records into one valid JSON array.

  1. 1Add files
  2. 2Options
  3. 3Convert
  4. 4Save
No installation · Processed in your browser

Preparing the converter…

Add filesDrop files here or choose them from your device.Drop here to add your files. Choose files JSONL, NDJSON, TXTJSONNo fixed byte cap · browser memory and format limits apply
Choose a file to check its format and size.

Related tools

Convert JSON to JSONLWrite each item in a JSON array as one JSONL record, optionally selecting a nested array path.Convert CSV to JSONParse a CSV header and rows into JSON records, choosing the input encoding and delimiter.Convert JSON to CSVExport an array of JSON objects as CSV rows, with an option to flatten nested fields.Format and validate JSONValidate JSON syntax and add readable indentation without changing the intended data structure.

Supported formats and settings

Input formats
JSONL, NDJSON, TXT
Output formats
JSON
Per-file limit
Current device memory
Total selected-file limit
Estimated by file count and format
Number of selectable files
1–1

Recommended input total: 8 MiB on mobile / 32 MiB on desktop. Low memory can reduce the effective limit.

Your files are not uploaded to a conversion server. A new result is created in your browser.

How to use this tool

  1. Choose files in JSONL, NDJSON, TXT format. Maximum files per batch: 1.
  2. Review Indentation, then start processing.
  3. Download the JSON result and check its content and quality.

What this tool does

  • Convert line-delimited JSONL or NDJSON records into one valid JSON array.
  • Read JSONL, NDJSON, TXT input and save the JSON result as a new file.
  • Available settings: Indentation.

Limitations

  • Every non-empty line must contain one complete JSON value. A malformed line stops conversion instead of being silently discarded.

Frequently asked questions

Convert JSONL to JSON Online — What should I check before using this tool?

Every non-empty line must contain one complete JSON value. A malformed line stops conversion instead of being silently discarded.

Which files can I choose?

Choose files in JSONL, NDJSON, TXT format. Maximum files per batch: 1.

How can I adjust the result?

Indentation.

Understand the formats

JSON

JSON represents objects, arrays, strings, numbers, booleans and null. Property names use double quotes; comments are not part of standard JSON.

Format JSON for inspection, flatten suitable records into a CSV table, or combine JSONL records into a JSON array.

JavaScript cannot represent every large integer exactly. CSV has no universal type system, so a JSON-to-CSV round trip can change types or nested structure. Keep the source data.

When is this useful?

Read JSONL or NDJSON as one array. Invalid lines are reported rather than silently discarded.

Input and result example

two valid JSON lines → two-element JSON array

Examples illustrate the workflow; actual size, support and recognition depend on the source and settings.

Related guides

Check CSV and Excel data before importFile conversion and error basics