What file format does this expect?

NDJSON, also called JSON Lines or JSONL — one complete JSON value per line with no wrapping array. Each line is parsed independently, so a single bad line does not break the rest of the view.

How are the table columns chosen?

The viewer scans the valid object lines and builds the column list from the union of their top-level keys, in first-seen order. Up to twelve columns are shown; nested objects and arrays appear as compact JSON in the cell.

What happens to invalid lines?

Lines that fail to parse are still listed, highlighted, and show the parse error instead of cell values, so you can see exactly which records are malformed without losing your place.

No. Parsing, filtering, and rendering all happen in your browser. The data is never sent to a server or stored anywhere.

JSON Lines / NDJSON Viewer

Browse NDJSON as a searchable table

The JSON Lines / NDJSON Viewer turns a stream of newline-delimited JSON into a readable table. Each line becomes a row, top-level keys become columns, and a single click expands any row to its full pretty-printed JSON. A search box filters the view across every field at once.

How it works

Each non-blank line is parsed independently with JSON.parse. Objects populate the table directly; other valid JSON values (numbers, arrays) are wrapped so they still display. Lines that fail to parse are kept in place, highlighted, and annotated with their error message, so malformed records stand out without disrupting the rest of the table.

Columns are derived from the union of top-level keys across the valid object rows, preserving the order in which keys first appear and capping the display at twelve columns for readability. Nested objects and arrays are rendered as compact JSON inside their cell. The search box performs a case-insensitive substring match against each line’s raw text, so a single term can match a value in any field.

Tips and notes

Use the viewer to sanity-check an export before loading it into BigQuery, Elasticsearch, or a log tool — the highlighted error rows show you immediately whether every line is well-formed. Click a row to inspect deeply nested structure that does not fit in a cell. For very large pastes the table renders the first 500 matching rows to stay responsive; narrow the result with the search box to focus on the records you care about.