Can I convert an RF64 file back to standard WAV?

Yes, but only if the audio data fits within the 4 GB limit. If the file is larger than 4 GB, it cannot be stored in a standard WAV. You would need to split the audio into multiple WAV files.

Why does my software say the file is corrupted when it plays fine on another computer?

The software on the first computer likely does not support RF64 or Wave64. The file is not corrupted; it is using an extended format that the software cannot read. Try updating the software or using a different application.

What is the difference between RF64 and Wave64?

RF64 replaces the "RIFF" identifier with "RF64" and adds a ds64 chunk for 64-bit sizes. Wave64 uses a completely different file structure and the .w64 extension. RF64 is more widely supported in professional audio software.

Can I record directly to RF64 on a portable recorder?

Some portable recorders labeled as bwf rf64 recorders support RF64. Check your recorder's manual or settings menu. If it does not, you may need to record in standard WAV and split or convert later.

WAV Files Over 4 GB: RF64, W64 and the Size Limit

Standard WAV files cap out at 4 GB. Their internal size fields are 32-bit. Record long multitrack sessions or high-resolution audio and you hit that wall. Extended formats RF64 and Sony Wave64 fix this with 64-bit sizes, but apps that don't support them may treat the file as corrupt or refuse to open it. Here's why the limit exists, which formats solve it, and what to do when a large WAV file won't open.

Why Standard WAV Hits a 4 GB Wall

The WAV format stores file sizes in 32-bit fields. A 32-bit unsigned integer tops out at 4 GiB. Some applications interpret these fields as signed integers, cutting the usable limit to 2 GiB. A standard WAV file cannot legally exceed 4 GiB, and many programs fail or corrupt data before reaching that boundary.

When the Limit Catches Up With You

At 48 kHz sample rate, 24-bit depth and stereo channels, audio consumes 288,000 bytes per second. That's about 1 GB per hour. A four-hour multitrack session or a high-resolution live recording pushes past the 4 GB ceiling faster than you'd think.

The RF64 Format (EBU Tech 3306)

RF64, defined by EBU Tech 3306, is the most common fix for exceeding the WAV size limit. Instead of the usual "RIFF" identifier at the start of the file, RF64 uses "RF64". It adds a special chunk called ds64 that stores the true 64-bit size values. RF64 files grow well beyond 4 GB without breaking the basic structure of the WAV format.

How RF64 Works

The ds64 chunk holds the actual data size and the overall file size. Standard WAV readers that don't recognize RF64 either refuse to open the file or read only the first 4 GiB of audio. Many modern digital audio workstations and professional recorders support RF64. Older or simpler tools may see the file as corrupted.

Sony Wave64 (.w64)

Sony developed Wave64 as an alternative 64-bit WAV variant. Its file structure differs from RF64, with its own header and chunk layout. Wave64 files carry the .w64 extension and appear in Sony recording hardware and some DAWs. Like RF64, Wave64 stores audio larger than 4 GB.

Wave64 isn't as widely supported as RF64. Compatibility can bite. If you receive a Wave64 file and your editor doesn't recognize it, convert it to a different format before editing or playback.

Why Large Files Look Corrupted in Older Tools

Open a large RF64 or Wave64 file in a program built only for standard WAV, and the program reads the header expecting a 32-bit size. It finds either an unknown "RF64" identifier or a ds64 chunk it cannot interpret. The application then rejects the file outright or tries to read it using wrong size information.

If the program reads only the first 4 GiB, you get a truncated file. It may show a normal length but contains only the beginning of the audio.
If the program misreads the header, it may report a corrupt file, show no waveform, or crash.

This is not actual corruption. The file is intact. The tool simply lacks the ability to parse the extended format.

FAT32 and Recorder File Splitting

Another common reason a WAV file is too big to open isn't the format itself but the storage medium. Many portable recorders use memory cards formatted as FAT32, which cannot store a single file of 4 GiB or larger. To work around this, the recorder splits long takes into multiple smaller files, often naming them with sequential numbers.

If you see a folder full of files from one session, they may be pieces of a single continuous take. Join them in an audio editor that supports concatenation or batch import. The split is a filesystem limitation, not a WAV format issue.

How to Handle Large WAV Files That Won't Open

Identify the Format First

Check whether the file is RF64 or Wave64. Look at the first few bytes in a hex viewer. If it starts with "RF64", it's RF64. If it starts with a Wave64 header, it's a .w64 file.

Open the file in a hex editor or a simple file inspector that shows the header bytes.
If the header says "RF64", use an application that supports RF64: recent versions of popular DAWs or audio converters.
If the file is Wave64, find a converter that handles .w64 files. Some tools convert Wave64 to standard WAV or RF64.
If the file is a standard WAV that exceeds 4 GB (rare but possible with some tools), split it into smaller segments using a utility that handles large files.

If no local application opens the file, the online service wav.repair may help, though its capabilities are limited to what is described here.

Choosing the Right Format for Future Recordings

If you regularly record long multitrack or high-resolution audio, switch to RF64 from the start. Many modern recorders and DAWs offer it as an option. If your recorder uses FAT32 cards and you anticipate takes longer than 4 GB, check whether it has a setting to split files automatically or to use a different file system like exFAT.

Some professional recorders are labelled bwf rf64 recorders, meaning they write Broadcast Wave Format with RF64 extensions. These files are more likely to work with broadcast and post-production tools. Test a small recording first. Confirm your playback application handles the format before you commit to a full session.