How to open a JSON file online
Three steps, a few seconds, no software.
Open your .ACF file
Drop it on the box, choose it from your device, or paste the data straight in.
View the structure
Your .ACF 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 .ACF file?
The most common data format on the web.
An ACF file is a Steam Application Cache File - a small plain-text record that Steam creates for each installed game, storing its ID, install path, disk size, and update state. Steam manages these files automatically; you do not need to open one in normal use. If Steam stops recognizing a game you already installed, the ACF file is almost always the cause.
Programs that open .ACF files
| Full name | Steam Application Cache File |
|---|---|
| Developer | Valve Corporation |
| First released | ~2003 (with Steam client) |
| Category | Text & Code |
| MIME type | text/plain |
Related viewers
Every viewer is free to use.
Frequently asked questions
Is my .ACF file uploaded anywhere?
No. The file is opened directly from the copy you pick.
My .ACF 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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