A JSONLint alternative for large JSON files
· 3 min read · By Amir Badi
JSONLint is where many people paste a snippet to see why it won't parse, and for that job it's good. It's harder to use when the JSON is a 300 MB export. You can't paste that comfortably into a text box, and a list of every line in the file doesn't help you find the one bad record. For files that size, try the GigaJSON JSON validator. It opens JSON files up to 1 GB in your browser and uploads nothing.
We make GigaJSON, so this is our view of where each tool fits, not an independent review. I checked JSONLint's pages on 6 November 2026.
What JSONLint does well
JSONLint calls itself "a validator and reformatter for JSON". You paste, type or give it a URL, and it points to the line with the error. Its about page says all tools run in your browser. The site has grown into about 40 tools (format, repair, minify, diff, CSV, YAML, schema, a path finder) and a paid Mac app.
Its web pages don't state a size limit. The one size claim I found is for the $6.99 Mac app, which lists "Large file support (10MB+)". The web tools are built around a text editor, and a text editor gets slow once it holds tens of megabytes.
Where GigaJSON is different: the file size
| You have | Start with |
|---|---|
| A snippet from a log or an API answer that won't parse | Either. JSONLint is fine, and so is the GigaJSON validator. |
| JSON copied from an AI chat with comments or trailing commas | JSON Repair shows each change before you keep it. |
| A file from 10 MB to 1 GB | GigaJSON. Open the file instead of pasting it. |
| A large file you then need to search, filter or edit | The GigaJSON app: tree, table, queries, diff and history on the same document. |
GigaJSON parses in a background worker and draws only the rows on screen, so the tab stays usable while a big file loads. In our October benchmark a 200 MB file opened in 2.1 s, 500 MB in 9.3 s and 1 GB in 18.3 s (medians of three runs on one laptop; the large-file guide has the details). Your file and machine will give other numbers.
When the JSON is invalid, you get the line and column of the problem and a Repair button when the error is one it can fix. A missing comma at line 4,812,003 of an export is easy to find this way.
Validating against a schema
JSONLint links a schema validator too. The GigaJSON JSON Schema validator supports drafts 4, 7, 2019-09 and 2020-12, and each error shows the path of the value and the rule it breaks. If you don't have a schema yet, the schema generator writes one from example data.
Limits to know
- The default limit is 512 MB, and you can raise it to 1 GB in Preferences. A 1 GB file needs several GB of free memory.
- The full text editor holds up to about 100 MB of formatted text. Past that you get a read-only text view, and you can edit one part at a time.
- CSV and YAML input and JSON repair are limited to 128 MB, and jq to about 20 MB.
- GigaJSON is a browser tool. For multi-gigabyte files or a script in a pipeline,
jqor a streaming parser is the better choice.
Try it with the file JSONLint couldn't take
Open the JSON validator and choose your file. If it's valid, open it in the app to look around in the tree or the table. If it isn't, the error points at the line, and Repair fixes the common cases. For a snippet, JSONLint still works fine.