How to open a JSON file online
Three steps, a few seconds, no software.
Open your .CNT file
Drop it on the box, choose it from your device, or paste the data straight in.
View the structure
Your .CNT file opens as a tidy, foldable tree, with the exact line of any error pointed out.
Search, copy or download
Search keys and values, copy any path or value, switch to a table, or download a clean copy.
What is a .CNT file?
The most common data format on the web.
A CNT file is a plain-text table-of-contents script that belongs to a Windows Help (.hlp) file from the WinHelp era (Windows 3.x through XP). Open it in Notepad or any text editor. The main concern is that WinHelp is obsolete. Windows 10 and 11 cannot open the matching .hlp files because Microsoft removed the WinHelp engine and no longer provides a replacement.
Programs that open .CNT files
| Full name | Microsoft Help Contents File |
|---|---|
| Developer | Microsoft |
| First released | 1990 (WinHelp, Windows 3.0 era); CNT format with WinHelp 4.0, Windows 95 |
| Category | Text & Code |
| MIME type | text/plain |
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Frequently asked questions
Is my .CNT file uploaded anywhere?
No. The file is opened directly from the copy you pick.
My .CNT file is invalid. Can you fix it?
We show the exact line and column of the first error. For common problems like comments, trailing commas, single quotes or Python-style True/False/None, click Try to repair and download the fixed file.
How large can the file be?
Up to 50 MB. The tree only builds the branches you open, so even multi-megabyte files stay responsive.
What is JSONPath?
A path like $.orders[3].customer.email that points to one value inside the data. Click any node to see its path and copy it for code, jq or your API docs.
Can I see my data as a table?
Yes. Any array of objects can be shown in the Table view and downloaded as CSV.
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