JSON array chunks

Client

Split a JSON array into smaller arrays of up to n elements each, or concatenate an array of arrays back into a single list—useful for batch jobs, pagination mocks, and reversing chunked exports.

Learn more: batching JSON arrays

Slice a single JSON array into fixed-size batches, or concatenate an array of batch arrays back into one flat array. This stays in structured JSON (no newline format)—handy next to other JSON utilities on this site.

When to chunk in JSON

APIs and workers often accept a maximum number of records per request. Splitting a large client-side array into chunks of n items lets you test those limits, build queue payloads, or simulate pagination without leaving the browser.

Merge vs NDJSON

NDJSON stores one value per line of text. Here, both input and output remain JSON arrays: split produces an array of arrays, merge flattens that shape. Choose NDJSON when a system expects lines; choose chunking when you want nested JSON you can pipe into compare, schema, or format tools.

Split or merge

?

Split requires a JSON array root. Merge requires a JSON array of arrays—each chunk must be its own array value.

Common use cases

  • Prepare fixed-size batches from a large JSON array for rate-limited APIs, queue workers, or upload slices.
  • Turn paginated responses stored as an array of pages (`[[…],[…]]`) into one list for diffing or analytics.
  • Prototype UI pagination: split mock data arrays without writing a script in your terminal.
  • After splitting for NDJSON or CSV pipelines, merge chunk files that were validated per batch.

Common mistakes to avoid

  • Passing an object or single value when splitting

    Split mode expects a JSON array at the root (`[ … ]`). Wrap objects in an array if you only have one record type.

  • Merging non-uniform chunks

    Merge mode expects each element of the outer array to be an array. Mixed types (for example an object in the list) will error with the index that failed.

  • Expecting chunk size to pad the last batch

    The last chunk is shorter when the array length is not divisible by the chunk size—this is normal and matches how most batch APIs slice arrays.

FAQ

Does this upload my JSON?

No. Parsing and chunking run entirely in your browser.

How is this different from NDJSON?

NDJSON is one JSON value per line of text. Here you stay in structured JSON: output is a JSON array of arrays, which is easier to feed back into other JSON tools on this site.

Can I chunk arrays of primitives and objects together?

Yes. Any valid JSON array elements are preserved inside each chunk—only the slicing changes.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • split json array into batches online
  • chunk json array for api pagination
  • merge json array of arrays

More tools

Related utilities you can open in another tab—mostly client-side.