What is the WFM file format?
.wfm files are binary waveform data files saved by Tektronix oscilloscopes, primarily the TDS 5000, TDS 6000, TDS 7000, and DPO 70000 series instruments. Each file captures a complete oscilloscope acquisition: raw sample data (voltage vs. time) together with a fixed-length header encoding all parameters needed to reconstruct the waveform - time scale, voltage scale, offset, sample rate, and record length.
The header is followed by the curve buffer, which stores raw samples as INT16 (2 bytes/sample), INT64 (8 bytes/sample), or FP32 (4 bytes/sample) depending on the instrument model. Fast-frame acquisitions store multiple frames sequentially, each with an individual timestamp. User marks, if set, are appended after the curve buffer at approximately 75 bytes each.
Tektronix documents four format revisions - LLWFM, WFM#001, WFM#002, and WFM#003 - described in manual 077-0220-11. The primary software reader, WaveStar, was discontinued in the early 2000s and is now available as unsupported legacy freeware. MATLAB users can import .wfm files using the wfm2read.m script; the sigrok open-source signal analysis project also provides a reader. The related .isf (Internal Storage Format) is a simpler sibling format from the same instrument families, often preferred for quick data export.
Security & safety
RISK: LOWScientific data file; no executable content. Contains only waveform samples and acquisition metadata.
Format details
in a nutshell- dBASE Form File - dBASE database IDE uses .wfm for form definitions that make up the UI of dBASE applications; unrelated to oscilloscope data.
Programs that open WFM files
Windows4 apps
dBASE
Paid Only relevant if the .wfm is a dBASE form file, NOT an oscilloscope file. Open via dBASE IDE. 
WaveStar Software for Oscilloscopes (WSTRO)
Free Download legacy version from Tektronix; install and open .wfm file via File → Open. Note: 32-bit only, unsupported since early 2000s, may require compatibility settings on Windows 10/11.
MATLAB (with wfm2read.m)
Paid Download wfm2read.m from MATLAB Central File Exchange; call wfm2read('file.wfm') to load data as array. Technical details
deep spec| Format type | Binary scientific instrumentation data file |
| Encoding | Binary, little-endian |
| Header | Fixed-length; encodes acquisition parameters: time scale, voltage scale, offsets, record length, sample format |
| Sample data types | INT16 (2 bytes/sample), INT64 (8 bytes/sample), or FP32 (4 bytes/sample) - instrument-dependent |
| Format revisions | LLWFM, WFM#001, WFM#002, WFM#003 - documented in Tektronix manual 077-0220-11 |
| Typical file size | 10 KB - 50 MB (depends on record length: 1k to 200M samples) |
| Maximum sample rate | Up to 200 GS/s on DPO70000 series instruments |
| Multi-frame support | Fast-framing mode stores sequential frames with per-frame timestamps |
| User marks | Appended after the curve buffer; approximately 75 bytes each |
| Primary software | WaveStar for Oscilloscopes (WSTRO) - discontinued; available as unsupported legacy freeware |
| Open-source/scripting support | sigrok project; MATLAB wfm2read.m script |
| Related format | .isf (Internal Storage Format) - simpler sibling format from the same Tektronix instrument families |
| Supported instruments | Tektronix TDS 5000, TDS 6000, TDS 7000, DPO 70000 series oscilloscopes |
| Released | 1990s (TDS 5000/6000/7000 series oscilloscopes) |
| Latest version | Reference Waveform File Format Manual 077-0220-11 (covers TDS5000-DPO70000 families) |
| Specification | download.tek.com |
WFM conversions
Community Q&A
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