A WAV file header is the metadata section at the beginning of every .wav file. It follows the RIFF (Resource Interchange File Format) specification and contains critical information such as the audio format (PCM, IEEE float, etc.), number of channels, sample rate, bit depth, and the size/location of the audio data chunk. Without a valid header, audio software cannot correctly interpret or play the file.

The RIFF structure contains several sub-chunks: "fmt " holds the audio format details (codec, channels, sample rate, bit depth); "data" contains the actual PCM or compressed audio samples; optional chunks like "fact" store the sample count for compressed formats, "LIST" may hold metadata (artist, title, copyright), and "bext" is used in Broadcast Wave Format for professional audio metadata including timestamps and originator info.

Duration is calculated using the formula: Duration = DataChunkSize / ByteRate, where ByteRate = SampleRate × NumChannels × (BitsPerSample / 8). For example, a CD-quality WAV (44,100 Hz, stereo, 16-bit) has a byte rate of 176,400 bytes per second. If the data chunk is 17,640,000 bytes, the duration is exactly 100 seconds. This tool automatically performs this calculation and displays the result.

PCM (Pulse Code Modulation, format tag 0x0001) stores audio samples as integer values (e.g., 16-bit signed integers ranging from -32,768 to +32,767). It is the most common and universally supported WAV format. IEEE Float (format tag 0x0003) stores samples as 32-bit or 64-bit floating-point numbers (typically ranging from -1.0 to +1.0), offering greater dynamic range and precision — preferred in professional DAWs and audio processing pipelines to avoid clipping during intermediate processing stages.

Several issues can cause this: (1) The data chunk size may not match the actual audio data length, causing players to truncate or fail; (2) The audio format codec may be unsupported by the player (e.g., A-law, μ-law, or ADPCM); (3) The file may use WAVE_FORMAT_EXTENSIBLE with a non-standard subformat GUID; (4) The file may be corrupted — the header says one thing but the data says another. This viewer helps you diagnose these mismatches by inspecting every field.

Broadcast Wave Format is an extension of the standard WAV format defined by the EBU (European Broadcasting Union). It adds a "bext" chunk containing professional metadata: description, originator, originator reference, origination date/time, timecode reference, and SMPTE UMID. BWF files also typically include a "mext" or "levl" chunk for loudness metadata. These files are widely used in broadcasting, film, and professional audio production.