CSV & DATA TOOLS
Free JSON Flatten online
Flatten nested JSON to dot notation.
JSON Flatten on DocTools helps you flatten nested JSON to dot notation, with no account needed. Drop your text into JSON Flatten, choose your settings, and save the finished file. JSON Flatten runs locally on your device, so nothing is uploaded to a server.
- Free to use
- No signup
- No uploads
- Works offline
Why use JSON Flatten
- flatten nested JSON to dot notation without installing software
- Your text is processed on your device by JSON Flatten, never uploaded
- JSON Flatten needs no account, email address or payment details
- JSON Flatten is batch-friendly: reuse it immediately on the next file
- JSON Flatten is keyboard accessible and screen-reader friendly
- JSON Flatten is free forever, with no watermark on the result
JSON Flatten runs entirely inside your browser. Your text is never uploaded, stored or shared, and nothing is retained once you close the tab.
How to use JSON Flatten
- Add your text Drag your text onto the drop zone or pick it from your device.
- Adjust the options Set the options that control how JSON Flatten handles your input.
- Process it JSON Flatten works instantly on your device, with no queue and no upload wait.
- Download the result Save the finished file straight to your device, then reuse the tool as often as you like.
Benefits
Private by design
Your text stays on your device while JSON Flatten works. JSON Flatten never sends it to a server, so confidential work stays confidential.
Instant results
JSON Flatten finishes most jobs in under a second because the work happens on your own hardware.
No signup, no limits
Use JSON Flatten as many times as you want. JSON Flatten asks for no account, adds no watermark and keeps no paid tier gating the output.
Works offline
Once the page has loaded, JSON Flatten keeps working without a connection, which helps on flights and locked-down networks.
Who it is for
For developers
Developers use JSON Flatten to debug and ship faster without installing software: flatten nested JSON to dot notation on a shared or locked-down machine.
For freelancers
JSON Flatten helps freelancers send client deliverables quickly, since your text never leaves the laptop it was created on.
For support teams
JSON Flatten helps support teams answer customer requests quickly, since your text never leaves the laptop it was created on.
How it works
JSON Flatten loads your text into memory, applies the change you requested to the underlying data rather than to a screenshot of it, and writes a fresh copy for download. Your original stays untouched on disk, and every step of JSON Flatten happens inside your browser sandbox.
Frequently asked questions
Is JSON Flatten free to use?
Yes. JSON Flatten is completely free with no account, no trial and no usage cap. Every feature on this page is available on the first visit.
Does JSON Flatten upload your text to a server?
No. JSON Flatten processes your text inside your browser, so it never reaches a DocTools server. That also means the tool keeps working if your connection drops mid-task.
Is there a file size limit?
The practical ceiling is your device's available memory rather than a server quota. Files up to roughly 100 MB work comfortably on a typical laptop in JSON Flatten.
Do I need to install anything to use JSON Flatten?
No installation is needed. JSON Flatten runs in Chrome, Edge, Firefox and Safari, on desktop and on mobile, with no extension or plugin.
Can I use JSON Flatten on a phone or tablet?
Yes. The JSON Flatten interface adapts to small screens and supports touch input, though very large jobs are faster on a desktop browser.
What happens to your text when I close the tab?
It is discarded. JSON Flatten keeps everything in temporary browser memory, so closing the tab removes every trace of the session.
Related tools
- Excel to JSON | Convert spreadsheet data to JSON format
- JSON to Excel | Convert JSON data into Excel spreadsheets
- JSON Key Extractor | Extract all keys from JSON
Last updated: 2026-09-07