How big a file can it open?

There's no fixed limit: the file is read 4 MB at a time and only what you keep is held, so gigabytes are fine. A filter that keeps most of a huge file needs memory for what it keeps.

What if some lines aren't valid JSON?

They're skipped and counted, and the first few are listed with their line numbers and text, so a cut-off last line or a stray log message doesn't stop the run.

No. Bracely runs entirely in your browser, so nothing you paste or open leaves your device.

Big files

Input

Output

Large JSON File Viewer and Filter

Log files, NDJSON exports and database dumps are often too big for any editor. Bracely reads them a few MB at a time, so a file of several gigabytes doesn't freeze or crash the tab: count its records and fields, run a jq filter on every record, keep the lines that contain some text, or convert a JSON array to JSON Lines, and download the result.

How do I use the Big files?

Open Big files and drop a .jsonl, .ndjson, .log or .json file, or a gzipped one. Any file too big for the editor opens here by itself.
Pick what to do: count records and fields, run a jq filter on each record, keep records that contain some text, or keep them all to convert.
Watch it read, then download what was kept, or open it in a new tab when it's small enough.

What does the Big files do?

Files of several gigabytes, read in pieces and never held whole
JSON Lines, a JSON array, or the array inside an object like {"data": […]}
jq on every record, with select, map and the other builtins
A summary of every field: how often it appears and its types
.gz files unpacked as they're read
Bad lines are skipped and listed with their line numbers

Frequently asked questions

How big a file can it open?: There's no fixed limit: the file is read 4 MB at a time and only what you keep is held, so gigabytes are fine. A filter that keeps most of a huge file needs memory for what it keeps.
What if some lines aren't valid JSON?: They're skipped and counted, and the first few are listed with their line numbers and text, so a cut-off last line or a stray log message doesn't stop the run.
Is my data uploaded?: No. Bracely runs entirely in your browser, so nothing you paste or open leaves your device.

More JSON tools

Bracely has more than 65 JSON tools in one page. Related ones:

Runs entirely in your browser. Nothing you paste is uploaded. Made by Saurabh Pagrut. About · Privacy policy
Last updated 21 October 2026 · Version 4.1 · Changelog
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