Open MF4 files in your browser
The measurement file of cars' test drives and test benches, from CANape, INCA and the loggers in the trunk. Open one right here, every channel on one timeline, with no CANape. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your measurement opens with its channels down one side, under their groups, and each channel as a curve in its unit on one timeline.
- Every channel in its unit • Scaled as the file says
- Two cursors • Lowest, highest, mean and RMS between them
- Find a channel by its name
- Export • PNG, and the values between the cursors as CSV
About MF4
Vector and Bosch made the Measurement Data Format in 1991 for their calibration tools, and ASAM took it over as MDF 4, saved as .mf4. Vector's CANape and CANoe, ETAS's INCA, dSPACE's ControlDesk and most CAN and FlexRay loggers record into it, and asammdf reads it in Python.
An MF4 is a tree of linked blocks: a header with who recorded it and when, data groups of channel groups, each a record of the channels sampled together, the conversions from their raw numbers to physical values in a unit, and the data, deflated from MDF 4.1 on, or packed with Zstandard or LZ4 in 4.3. A logger's bus frames are channels too, each CAN frame's ID and bytes, which only a DBC turns into signals.
Filepeek reads it in your browser a slice at a time and draws every channel as a curve in its physical unit on one timeline, under its channel group: linear, rational and table conversions worked out, and value tables as labels. A bus log's CAN frames are decoded into their signals when its DBC is dropped with it, and MDF 3's older .mdf files open the same way. Drag or pinch to move and zoom, put two cursors to read each channel between them, find a channel by its name, and save the view as PNG or the values between the cursors as CSV.
ASAM MDF 4 measurement file
.mf4
Format
- MIME type
- application/x-mf4
- Made by
- Vector and Bosch, now ASAM
Inside the file
- Header
- Who recorded it, when, and for which project
- Channel groups
- Channels sampled together, record by record
- Conversions
- From raw numbers to physical values
- Bus frames
- A logger's CAN frames, their IDs and bytes
Opens in every browser
Filepeek opens MDF 3 and MDF 4 files, compressed or not, in Chrome, Edge, Firefox and Safari. On their own, browsers only download them.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open MF4
- WindowsCANape or INCA • asammdf's viewer, free
- Macasammdf's viewer, free
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
How do I open an MF4 file without CANape?
Drop it on this page or choose Peek an MF4. Every channel opens on one timeline in your browser, under its channel group, on a phone too.
Can I decode the CAN frames a logger recorded?
Yes. A bus log keeps each frame's ID and bytes. Drop it with the DBC that describes them, or a folder with both, and each message's signals open in their units, named values as labels.
Does it open MDF 3 files?
Yes. MDF 3's .mdf files, from INCA and older loggers, open by their first bytes like an MF4. Alcohol 120%'s disc images are named .mdf too, and still open as discs.
Are compressed files read?
Yes. Deflated data blocks, and the transposed ones MDF 4.1 brought, are unpacked as they're read, and so are MDF 4.3's Zstandard and LZ4 blocks.
Why is a channel missing?
A channel timed by an angle or a distance instead of time isn't drawn, and neither are arrays, and the note over the lanes says how many it left out.