Need a big JSON file to test a parser, an import or an upload limit? Pick a size from 100 KB to 1 GB, or type your own, then choose the data (orders, customers, products, blog posts, users or log events) and the format: JSON, JSON Lines, CSV or XML. The file is written in front of you, with its size, record count, time and speed, and you can download it or open it in GigaJSON.
How to use it
- Click a size card, or Custom to type any size up to 1 GB.
- Choose the kind of data and the format (JSON, JSON Lines, CSV or XML), then click Generate.
- Watch the file being written. When it's done, download it or open it in GigaJSON.
Private, and made for big files
This tool runs in your browser, in a background worker: the file is made on your computer and never uploaded, and nothing is kept after you leave. Files up to 1 GB are written in pieces, so the page keeps responding. If your connection drops while you're here, the tool keeps working. When one tool isn't enough, GigaJSON opens your data with a tree, a table, JSONPath/JMESPath/jq queries, transforms, diff and history.
Questions
What does the data look like?
Realistic but made up. Orders have a customer, items, totals and tags; customers have contact details and spend; products have prices, stock and ratings; posts have an author, a body and comments; users have a profile and settings; log events have a level, a request and its timing. The same choices always give the same file.
How large can the file be?
Up to 1 GB on a computer, and 50 MB on a phone. The file is written in 8 MB pieces in a background worker, so the page keeps responding, and it's never held as one huge string. You can stop it at any time.
Can I open a 1 GB file in GigaJSON?
Yes, if you raise the limit: GigaJSON opens documents up to 512 MB by default, and up to 1 GB after you change Preferences, Largest document. The page tells you when a file is over your limit.
Is anything uploaded?
No. The file is generated on your computer and saved from there. Nothing is sent to a server.
All tools
- JSON FormatterIndent with 2 or 4 spaces, sort keys
- JSON ValidatorLine and column of the first error
- JSON MinifierRemove whitespace, see the bytes saved
- JSON RepairFixes quotes, commas, comments, AI output
- JSON Schema GeneratorA JSON Schema from examples
- Large JSON ViewerTree, table and search for huge files
- JSON Lines ViewerJSONL and NDJSON logs as a table
- JSON VisualizerThe data as a graph, PNG and SVG export
- JSON DiffChanges between two documents
- JSON Path FinderClick a value, copy its path
- JSONPath TesterJSONPath, JMESPath and jq, live
- JMESPath PlaygroundJMESPath, for AWS CLI queries too
- jq PlaygroundReal jq in your browser
- JSON to CSVNested objects become dotted columns
- CSV to JSONDelimiters detected, 007 stays 007
- JSON to XML@keys become attributes
- XML to JSONRSS feeds, sitemaps, SOAP responses
- JSON to YAMLReadable YAML, ambiguous strings quoted
- YAML to JSONAnchors and multiple documents
- JSON Lines to JSONNDJSON or JSONL into one array
- JSON to TypeScriptInterfaces inferred from your data
- JWT DecoderHeader, payload and expiry, locally
- JSON EscapeText to a JSON string and back
- Sample JSON FilesDownload test JSON, 100 KB to 1 GB
- Sample CSV FilesDownload test CSV, 100 KB to 1 GB
- Sample XML FilesDownload test XML, 100 KB to 1 GB
- Large JSON File GeneratorTest data from 100 KB to 1 GB