IMA to SNDR Converter

Transform IMA ADPCM audio into SNDR format online

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Gaming and embedded

Transform IMA recordings into SNDR — bringing headerless audio into a format with real-world usability.

Data Security

Your IMA files are erased immediately after processing. SNDR results are cleaned from our servers within 24 hours.

Instant Access

Open your browser and convert — no software installation needed. Works on Chrome, Firefox, Safari, and Edge.

How to convert IMA to SNDR

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose sndr or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your sndr file right afterwards

About formats

IMA ADPCM (Adaptive Differential Pulse-Code Modulation) is a compact audio coding standard published by the Interactive Multimedia Association in 1992, addressing the need for a lightweight, royalty-free compression scheme suitable for early multimedia PCs and embedded devices. The algorithm encodes each sample as a 4-bit nibble representing the quantized difference from the previous sample, while an adaptive step-size table adjusts dynamically to track signal amplitude — delivering a fixed 4:1 compression ratio over 16-bit PCM. Decoding requires only an integer multiply-add per sample and a small lookup table, so even modest 1990s CPUs could decompress in real time without dedicated DSP. The format became deeply embedded in the multimedia landscape: Microsoft adopted it as a standard ACM codec for WAV files, game engines relied on it for sound effects, and telephony equipment used it for voice storage. Its advantages are enduring: predictable 4:1 size reduction simplifies buffer allocation in constrained environments, the decode path runs on 8-bit microcontrollers, and the open specification made IMA ADPCM one of the most broadly implemented audio codecs in computing history.
Initial release: 1992
SNDR is the audio file format produced by Sounder, an early MS-DOS sound recording and playback utility from the early 1990s. Before Windows brought multimedia to the mainstream, Sounder was among a handful of DOS programs that let PC users capture and play audio through rudimentary hardware — often the PC speaker itself or early 8-bit sound cards. The format stores 8-bit unsigned PCM samples without any file header, relying on application defaults to determine playback parameters. Sample rates were typically low (4000 to 11025 Hz), reflecting hardware limits and storage costs when a 20 MB hard drive was considered generous. One practical advantage was absolute minimalism — with zero overhead bytes, every bit of the file was audio data, which mattered when storage was measured in kilobytes. The format could be piped directly to sound hardware without parsing, making real-time playback feasible on slow processors. Despite its simplicity, SNDR holds a place in computing history as one of the formats that brought digital audio to ordinary PCs. Files from this era occasionally surface in retrocomputing archives. SoX and ffmpeg can interpret SNDR files given the correct parameters, enabling preservation of early digital audio recordings.
Developer: Sounder (MS-DOS)
Initial release: 1991

Frequently Asked Questions

Why convert IMA to SNDR?

IMA ADPCM is headerless and hard to use outside embedded systems. SNDR provides a proper format with broad compatibility.

What applications open SNDR files?

SOX and retro computing utilities can handle SNDR files. Most are available as free downloads for major operating systems.

How is the SNDR audio quality?

SNDR provides good quality at standard settings. The output clarity depends on the original IMA recording quality.

How fast is the conversion?

Processing is fast — IMA files are lightweight and SNDR encoding completes in seconds on our server hardware.

Are my files kept private?

Your IMA files are erased after conversion completes. SNDR downloads are purged from our servers within 24 hours automatically.

Do I need to register?

No account required. Upload your file, convert, and download the result directly from your browser at convertio.tools.