DBC viewer and editor online
Open a DBC file in your browser to see every message and signal with its bit layout. Edit them, add new ones and export the result as a DBC. You don’t need a log, and nothing is uploaded.
Free. No account.
Open a DBC fileFiles are processed on your computer and never uploaded.
How to view and edit a DBC file online
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Open the app
Go to app.freecanstudio.com in a desktop browser. There is nothing to install and no account to create.
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Open the DBC
Drop the .dbc file on the window, or click Open DBC… and choose it, then pick Database in the view switcher. Its messages are listed in the sidebar.
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Edit and export
Select a message to see its signals and a grid of the bits they use. Edit a signal, add a message with New Message, then click Export DBC… to save the file.
Questions
What does the DBC viewer show?
Every message with its ID and length, and every signal with its start bit, length, byte order, sign, factor, offset, range, unit and receivers. A layout grid shows which bits each signal uses.
Which parts of a DBC are supported?
Standard and extended IDs; Intel and Motorola byte order; unsigned, signed and IEEE float signals; simple and extended multiplexing (SG_MUL_VAL_); comments, value descriptions and value tables; attributes, kept on export; and J1939 and CAN FD messages marked with VFrameFormat.
Is anything lost when I export?
Parts of a DBC outside FreeCAN Studio’s model are dropped when the file is opened, so an export leaves them out: signal groups, environment variables, relation attributes, network comments and BO_TX_BU_.
Can I decode a log with it?
Yes. Open a log as well and every matching frame is decoded. You can load several DBCs at once, each for every bus or for one bus, and J1939 messages match by PGN.
Are my edits kept?
Open DBCs and your edits are kept in your browser’s storage, so a reload doesn’t lose them. Nothing is uploaded. Export DBC… writes a file you can keep or share.
Is my DBC uploaded?
No. FreeCAN Studio runs in your browser: a Rust core compiled to WebAssembly reads the file on your computer. The app loads nothing from third parties, and its Content-Security-Policy makes your browser enforce that. How to check it.
Which browsers does it run in?
Current desktop versions of Chrome, Edge, Firefox and Safari. Phones and tablets are not supported.
Is it free?
Yes. FreeCAN Studio is free and needs no account. FreeCAN Studio Pro, a paid desktop app, is planned separately.
Want to look around first? The demo opens a 1,000,000-frame log with its DBC.
Try the Demo