Free viewer · test data

Open your MDF4, NI TDMS, CSV, Excel, GPX, FIT and TCX files for free

Received a measurement file but don't have the software to open it? Thanks to NeydFlow, a free viewer is available: it opens and displays your test data right in your browser, with no software to install. All you need is a free NeydFlow account.

Why a free viewer?

Test data files travel between benches, labs, suppliers and customers. But each format is often tied to specific software, sometimes expensive or installed on only a few machines. NeydFlow's free viewer lets anyone look at the measurements, check a file they received or share a curve, with nothing to install.

Supported formats

.MF4 · .MDF

MDF4 (ASAM MDF)

The automotive standard for CAN bus measurements and in-vehicle data loggers. Binary and compact, it holds many signals sampled at different rates.

.TDMS

NI TDMS

National Instruments' format, produced by LabVIEW, VeriStand or DIAdem. It organises data into file, groups and channels, with properties such as units, sample rate and start time.

.CSV · .TXT

CSV

The universal text format, exported by most cyclers, data loggers and acquisition software. Comma or semicolon separated, one column per measurement channel.

.XLSX · .XLS

Excel

Widely used to exchange test results and cycler exports, often with several sheets and descriptive headers.

.GPX

GPX

The exchange format for GPS tracks: position, altitude and timestamps. Useful for road tests and validation drives.

.FIT · .TCX

FIT and TCX

Formats from connected sensors and bike computers: speed, power, heart rate, cadence. Useful for field tests, e-bikes and light mobility.

How it works

  1. Create your free NeydFlow account and open the free viewer.
  2. Load your MDF4, TDMS, CSV, Excel, GPX, FIT or TCX file.
  3. Pick the channels to display and explore your curves.

When one file is no longer enough

Comparing dozens of tests, applying the same calculations to a whole campaign, sharing results with a team: that is what the NeydFlow platform is for. See the test data post-processing page.

To understand what each format contains and avoid common pitfalls, read our test data file formats guide.

FAQ

Frequently asked questions

How can I open an MDF4 file for free?

Create a free NeydFlow account: its free viewer opens MDF4 files in your browser, with no software to install.

How can I open a TDMS file without LabVIEW?

NeydFlow's free viewer reads NI TDMS files without LabVIEW or DIAdem: load the file and display its measurement channels.

What is a TDMS file?

TDMS is National Instruments' file format. It stores measurement channels organised in groups, with properties such as unit or sample rate. It often comes with a .tdms_index file, which only speeds up reading.

What is an MDF4 file?

MDF4 is the measurement data format standardised by ASAM, widely used in automotive to record CAN bus and on-board sensor signals.

Is the free viewer really free?

Yes. The free viewer is available with the free NeydFlow account: just sign up to open and view your files.

Contact

Let's talk about your test project.

A first conversation with no commitment, in English or French.

contact@bertrand-consulting.fr
+33 6 33 72 47 43
Contact me