Convert IMA Files Free
Professional IMA file conversion tool
Drop your files here
or click to browse files
Supported Formats
Convert between all major file formats with high quality
Common Formats
MPEG-1 Audio Layer III - the most universal audio format worldwide, using lossy compression to reduce file sizes by 90% while maintaining excellent perceived quality. Perfect for music libraries, podcasts, portable devices, and any scenario requiring broad compatibility. Supports bitrates from 32-320kbps. Standard for digital music since 1993, playable on virtually every device and platform.
Waveform Audio File Format - uncompressed PCM audio providing perfect quality preservation. Standard Windows audio format with universal compatibility. Large file sizes (10MB per minute of stereo CD-quality). Perfect for audio production, professional recording, mastering, and situations requiring zero quality loss. Supports various bit depths (16, 24, 32-bit) and sample rates. Industry standard for professional audio work.
Ogg Vorbis - open-source lossy audio codec offering quality comparable to MP3/AAC at similar bitrates. Free from patents and licensing restrictions. Smaller file sizes than MP3 at equivalent quality. Used in gaming, open-source software, and streaming. Supports variable bitrate (VBR) for optimal quality. Perfect for applications requiring free codecs and good quality. Growing support in media players and platforms.
Advanced Audio Coding - successor to MP3 offering better quality at same bitrate (or same quality at lower bitrate). Standard audio codec for Apple devices, YouTube, and many streaming services. Supports up to 48 channels and 96kHz sample rate. Improved frequency response and handling of complex audio. Perfect for iTunes, iOS devices, video streaming, and modern audio applications. Part of MPEG-4 standard widely supported across platforms.
Free Lossless Audio Codec - compresses audio 40-60% without any quality loss. Perfect bit-for-bit preservation of original audio. Open-source format with no patents or licensing fees. Supports high-resolution audio (192kHz/24-bit). Perfect for archiving music collections, audiophile listening, and scenarios where quality is paramount. Widely supported by media players and streaming services. Ideal balance between quality and file size.
MPEG-4 Audio - AAC or ALAC audio in MP4 container. Standard audio format for Apple ecosystem (iTunes, iPhone, iPad). Supports both lossy (AAC) and lossless (ALAC) compression. Better quality than MP3 at same file size. Includes metadata support for artwork, lyrics, and rich tags. Perfect for iTunes library, iOS devices, and Apple software. Widely compatible across platforms despite Apple association. Common format for purchased music and audiobooks.
Windows Media Audio - Microsoft's proprietary audio codec with good compression and quality. Standard Windows audio format with native OS support. Supports DRM for protected content. Various profiles (WMA Standard, WMA Pro, WMA Lossless). Comparable quality to AAC at similar bitrates. Perfect for Windows ecosystem and legacy Windows Media Player. Being superseded by AAC and other formats. Still encountered in Windows-centric environments and older audio collections.
Lossless Formats
Apple Lossless Audio Codec - Apple's lossless compression reducing file size 40-60% with zero quality loss. Perfect preservation of original audio like FLAC but in Apple ecosystem. Standard lossless format for iTunes and iOS. Supports high-resolution audio up to 384kHz/32-bit. Smaller than uncompressed but larger than lossy formats. Perfect for iTunes library, audiophile iOS listening, and maintaining perfect quality in Apple ecosystem. Comparable to FLAC but with better Apple integration.
Monkey's Audio - high-efficiency lossless compression achieving better ratios than FLAC (typically 55-60% of original). Perfect quality preservation with zero loss. Free format with open specification. Slower compression/decompression than FLAC. Popular in audiophile communities. Limited player support compared to FLAC. Perfect for archiving when maximum space savings desired while maintaining perfect quality. Best for scenarios where storage space is critical and processing speed is not.
WavPack - hybrid lossless/lossy audio codec with unique correction file feature. Can create lossy file with separate correction file for lossless reconstruction. Excellent compression efficiency. Perfect for flexible audio archiving. Less common than FLAC. Supports high-resolution audio and DSD. Convert to FLAC for universal compatibility.
True Audio - lossless audio compression with fast encoding/decoding. Similar compression to FLAC with simpler algorithm. Open-source and free format. Perfect quality preservation. Less common than FLAC with limited player support. Perfect for audio archiving when FLAC compatibility not required. Convert to FLAC for broader compatibility.
Audio Interchange File Format - Apple's uncompressed audio format, equivalent to WAV but for Mac. Stores PCM audio with perfect quality. Standard audio format for macOS and professional Mac audio applications. Supports metadata tags better than WAV. Large file sizes like WAV (10MB per minute). Perfect for Mac-based audio production, professional recording, and scenarios requiring uncompressed audio on Apple platforms. Interchangeable with WAV for most purposes.
Modern Formats
Opus Audio Codec - modern open-source codec (2012) offering best quality at all bitrates from 6kbps to 510kbps. Excels at both speech and music. Lowest latency of modern codecs making it perfect for VoIP and real-time communication. Superior to MP3, AAC, and Vorbis at equivalent bitrates. Used by WhatsApp, Discord, and WebRTC. Ideal for streaming, voice calls, podcasts, and music. Becoming the universal audio codec for internet audio.
{format_webm_desc}
Matroska Audio - audio-only Matroska container supporting any audio codec. Flexible format with metadata support. Can contain multiple audio tracks. Perfect for audio albums with chapters and metadata. Part of Matroska multimedia framework. Used for audiobooks and multi-track audio. Convert to FLAC or MP3 for universal compatibility.
Legacy Formats
MPEG-1 Audio Layer II - predecessor to MP3 used in broadcasting and DVDs. Better quality than MP3 at high bitrates. Standard audio codec for DVB (digital TV) and DVD-Video. Lower compression efficiency than MP3. Perfect for broadcast applications and DVD authoring. Legacy format being replaced by AAC in modern broadcasting. Still encountered in digital TV and video production workflows.
Dolby Digital (AC-3) - surround sound audio codec for DVD, Blu-ray, and digital broadcasting. Supports up to 5.1 channels. Standard audio format for DVDs and HDTV. Good compression with multichannel support. Perfect for home theater and video production. Used in cinema and broadcast. Requires Dolby license for encoding.
Adaptive Multi-Rate - speech codec optimized for mobile voice calls. Excellent voice quality at very low bitrates (4.75-12.2 kbps). Standard for GSM and 3G phone calls. Designed specifically for speech, not music. Perfect for voice recordings, voicemail, and speech applications. Used in WhatsApp voice messages and mobile voice recording. Efficient for voice but inadequate for music.
Sun/NeXT Audio - simple audio format from Sun Microsystems and NeXT Computer. Uncompressed or μ-law/A-law compressed audio. Common on Unix systems. Simple header with audio data. Perfect for Unix audio applications and legacy system compatibility. Found in system sounds and Unix audio files. Convert to WAV or MP3 for modern use.
{format_mid_desc}
RealAudio - legacy streaming audio format from RealNetworks (1990s-2000s). Pioneered internet audio streaming with low-bitrate compression. Obsolete format replaced by modern streaming technologies. Poor quality by today's standards. Convert to MP3 or AAC for modern use. Historical importance in early internet audio streaming.
Specialized Formats
DTS Coherent Acoustics - surround sound codec competing with Dolby Digital. Higher bitrates than AC-3 with potentially better quality. Used in DVD, Blu-ray, and cinema. Supports up to 7.1 channels and object-based audio. Perfect for high-quality home theater. Premium audio format for video distribution. Convert to AC-3 or AAC for broader compatibility.
Core Audio Format - Apple's container for audio data on iOS and macOS. Supports any audio codec and unlimited file sizes. Modern replacement for AIFF on Apple platforms. Perfect for iOS app development and professional Mac audio. No size limitations (unlike WAV). Can store multiple audio streams. Convert to M4A or MP3 for broader compatibility outside Apple ecosystem.
VOC (Creative Voice File) - audio format from Creative Labs Sound Blaster cards. Popular in DOS era (1989-1995) for games and multimedia. Supports multiple compression formats and blocks. Legacy PC audio format. Common in retro gaming. Convert to WAV or MP3 for modern use. Important for DOS game audio preservation.
Speex - open-source speech codec designed for VoIP and internet audio streaming. Variable bitrate from 2-44 kbps. Optimized for speech with low latency. Better than MP3 for voice at low bitrates. Being superseded by Opus. Perfect for voice chat, VoIP, and speech podcasts. Legacy format replaced by Opus in modern applications.
{format_dss_desc}
How to Convert Files
Upload your files, select output format, and download converted files instantly. Our converter supports batch conversion and maintains high quality.
Frequently Asked Questions
What is IMA ADPCM format?
IMA ADPCM (Interactive Multimedia Association Adaptive Differential Pulse Code Modulation) is a standardized audio compression algorithm from early 1990s. Designed for CD-ROM games, multimedia applications, and voice storage when disk space was expensive. Achieves 4:1 compression ratio (16-bit PCM down to 4-bit ADPCM) while maintaining acceptable voice quality. Not high-fidelity by modern standards, but revolutionary for 1990s CD-ROM multimedia boom.
Technical details: stores differences between consecutive samples (differential) with adaptive quantization adjusting compression based on signal characteristics. Each sample is 4 bits instead of 16 bits (4× smaller files). Decompression is computationally simple - crucial for 1990s computer CPUs. Suitable for voice, acceptable for sound effects, poor for music. Telephony-quality audio at a fraction of uncompressed size.
Should I convert IMA ADPCM to WAV or MP3?
Converting IMA ADPCM makes sense:
Limited Compatibility
Many modern players don't support IMA ADPCM. Convert to WAV for universal playback.
Quality Already Lost
IMA ADPCM is lossy - compression already degraded audio. Converting doesn't lose more quality. Access is the goal.
Embedded in Other Formats
IMA ADPCM often inside WAV, AVI, or game files. Extraction/conversion makes audio accessible separately.
Obsolete Codec
IMA ADPCM is 1990s technology. Modern codecs far superior. Convert to standard formats before tools vanish.
Convert IMA ADPCM to WAV for archival (preserves existing quality). Use MP3 if distributing and want smaller files. IMA quality already limited; conversion doesn't hurt further.
How does IMA ADPCM compression work?
IMA ADPCM algorithm principles:
Differential Encoding
Stores difference between consecutive samples, not absolute values. Audio changes gradually; differences are smaller than full values.
Adaptive Quantization
Algorithm adjusts quantization step based on signal. Large steps for rapid changes, small steps for gradual changes. 'Adaptive' in ADPCM.
4-bit Samples
Each compressed sample is 4 bits (vs 16-bit PCM). Achieves 4:1 compression ratio. 16-bit audio becomes 4-bit deltas.
Prediction
Algorithm predicts next sample based on previous samples. Encodes prediction error, not actual value. Efficient for correlated signals (voice).
Lossy Compression
Quantization discards information permanently. Decompression reconstructs approximation, not exact original. Acceptable for voice, problematic for music.
Low CPU Cost
Simple algorithm enables real-time decompression on 1990s CPUs. Critical advantage over complex codecs. Simplicity over quality.
Standardized
IMA (Interactive Multimedia Association) standardized the algorithm. Multiple vendors implemented compatibly. Industry coordination.
IMA ADPCM trades quality for compression and CPU efficiency. Perfect for 1990s multimedia; primitive by modern standards.
How do I convert IMA ADPCM to WAV?
FFmpeg handles IMA ADPCM excellently: `ffmpeg -i input.wav -codec:a pcm_s16le output.wav` if IMA ADPCM is inside WAV container. FFmpeg auto-detects IMA ADPCM and decompresses to PCM. For standalone IMA files: `ffmpeg -f adpcm_ima_wav -i input.ima output.wav`. FFmpeg supports multiple IMA ADPCM variants (WAV, QuickTime, various game formats).
SoX (Sound eXchange) also works: `sox input.wav output.wav` decompresses IMA ADPCM to PCM automatically. SoX is excellent for batch audio conversions. Cross-platform, free, handles many obscure formats. For IMA ADPCM conversions, both FFmpeg and SoX are reliable choices.
For game-embedded IMA ADPCM: specialized game audio extraction tools (VGMStream, foobar2000 with game audio plugins) can extract and convert. Many games store IMA ADPCM inside proprietary containers. Generic converters fail; game-specific tools understand container formats and extract audio properly.
What quality is IMA ADPCM audio?
Telephone quality - 8kHz sample rate typical (though higher rates possible), mono, 4:1 compression introduces noticeable artifacts. Speech is intelligible but has slightly robotic quality - quantization noise, reduced naturalness, less dynamic range. For voice messages, game dialogue, narration - acceptable. For music - poor quality with audible compression artifacts.
Compression artifacts: slight buzziness, rough texture on sustained sounds, loss of high-frequency detail, reduced dynamics. These are characteristic ADPCM artifacts from aggressive quantization. 1990s applications accepted this trade-off for storage savings. Modern ears accustomed to MP3/AAC hear IMA ADPCM as noticeably degraded.
Converting to WAV doesn't improve quality - just decompresses what's there. If IMA ADPCM was 8kHz/4-bit with artifacts, WAV output reflects that limited quality. You're rescuing audio from obsolete format, not restoring quality. Accept IMA ADPCM for what it is: 1990s compressed voice optimized for storage efficiency on CD-ROMs with limited capacity.
Where was IMA ADPCM commonly used?
CD-ROM multimedia: 1990s encyclopedias (Encarta, Compton's), educational software (Where in the World is Carmen Sandiego?, Oregon Trail), multimedia presentations. CD-ROM held 650MB - huge in 1993 but small for full-motion video and hours of narration. IMA ADPCM let developers fit more voice content on limited CD space.
Video games: Many 1990s-early 2000s PC and console games used IMA ADPCM for dialogue and sound effects. Memory and disk space were constrained. Uncompressed audio was luxury. IMA ADPCM provided acceptable voice quality at fraction of PCM size. Games from Westwood Studios, LucasArts, Sierra, and many others employed IMA ADPCM.
Embedded systems: Voice prompts in ATMs, industrial equipment, kiosks, phone systems - applications needing voice playback on limited hardware. IMA ADPCM's low CPU requirements and small file sizes made it ideal for embedded systems with minimal processing power and storage. Still occasionally used in budget embedded applications.
Can modern media players play IMA ADPCM?
Sometimes, depends on container: If IMA ADPCM is inside standard WAV file, many players support it (VLC, foobar2000, ffplay). Codec support is reasonably common. However, IMA ADPCM in proprietary game formats requires specialized tools. Raw .ima files without container may not be recognized.
Windows Media Player: historically had IMA ADPCM codec built-in (part of Windows codecs). Modern Windows 10/11 maintains support. VLC: excellent IMA ADPCM support via libavcodec (FFmpeg library). iTunes/Apple Music: supports IMA ADPCM in CAF and QuickTime containers but not common usage.
Practical reality: while codec support exists, many users have playback issues due to container confusion, codec detection failures, or non-standard implementations. Converting to uncompressed WAV eliminates playback uncertainty. For reliable access, conversion is safer than depending on player codec support.
IMA ADPCM vs other ADPCM variants?
ADPCM format comparison:
IMA ADPCM (Standard)
Interactive Multimedia Association standardized version. Most common, widest support. 4:1 compression, simple algorithm.
MS ADPCM
Microsoft's ADPCM variant. Similar to IMA but different coefficient tables. Used in Windows multimedia applications.
Dialogic ADPCM
OKI/Dialogic variant for telephony hardware. Seen in call center equipment, voice mail systems. Proprietary implementation.
DVI ADPCM
Digital Video Interactive format. IMA ADPCM is based on DVI ADPCM. Closely related, sometimes interchangeable.
Quality Similar
All ADPCM variants achieve ~4:1 compression with comparable voice quality. Differences in implementation details, not fundamental quality.
IMA ADPCM is standardized variant with best compatibility. Other ADPCM types need specific decoders. Convert all to WAV for compatibility.
Why did IMA ADPCM become obsolete?
Better codecs emerged: MP3 (1993), AAC (1997), Vorbis (2000), Opus (2012) offered dramatically better quality at similar or lower bitrates. These codecs use sophisticated psychoacoustic modeling - analyze human hearing to optimize compression. IMA ADPCM's simple algorithm couldn't compete. Quality difference was obvious; users migrated to better codecs.
Storage became cheap: IMA ADPCM solved 1990s problem (expensive disk space). By 2000s, hard drives were hundreds of gigabytes. Storage scarcity disappeared. Compression for space saving lost importance. Quality became priority. Uncompressed audio or high-quality lossy codecs replaced ADPCM. Technical constraint that justified IMA ADPCM vanished.
CPU power increased: Modern CPUs decode MP3/AAC in real-time effortlessly. 1990s CPUs struggled with complex codecs - IMA ADPCM's simplicity was necessity. Today, codec complexity doesn't matter; CPU cycles are abundant. No reason to use simple/inferior codec when CPU handles sophisticated codecs easily. IMA ADPCM's advantage (low CPU cost) became irrelevant.
What's inside IMA ADPCM file structure?
IMA ADPCM format components:
Usually in Container
IMA ADPCM rarely standalone. Typically inside WAV, AVI, game archives. Container provides file structure; IMA ADPCM is codec.
ADPCM Data Blocks
Audio stored as blocks of compressed 4-bit samples. Block size varies (common: 256, 512, 1024 samples). Decoder processes block-by-block.
Predictor State
Each block includes initial predictor value and step index. Enables independent block decoding without previous blocks.
No Metadata
IMA ADPCM codec doesn't include metadata. Container (WAV, AVI) provides sample rate, channels, length info.
Simple Structure
Binary compressed data, no fancy features. Straightforward encoding designed for 1990s hardware efficiency.
Format Variants
IMA ADPCM has variants (WAV, QuickTime, AVI) with slightly different frame structures. Core algorithm same, framing differs.
Endianness
Typically little-endian (Intel/x86 platforms). Big-endian variants exist for Mac/PowerPC. Platform-dependent.
Decoder Required
IMA ADPCM data is meaningless without decoder. Playback software needs ADPCM codec to reconstruct PCM.
Block Independence
Blocks decode independently. Enables seeking in audio streams without decoding entire file. Design advantage.
Documentation Available
IMA specification is public. Multiple implementations exist. Well-documented standard despite obsolescence.
Can I create IMA ADPCM files today?
Technically yes, but why? IMA ADPCM is obsolete codec with poor quality. Modern alternatives (Opus at low bitrates, AAC-LC, MP3) sound far better. Creating IMA ADPCM produces files with worse quality than necessary and limited compatibility. There's no good reason to encode IMA ADPCM in 2020s except extremely niche embedded system requirements.
If you must: FFmpeg encodes IMA ADPCM: `ffmpeg -i input.wav -codec:a adpcm_ima_wav output.wav`. But this is technological regression. Modern codecs achieve better quality at lower bitrates with universal playback support. IMA ADPCM made sense in 1993, not today.
Exception: legacy embedded systems still using IMA ADPCM decoders might require new audio in IMA format. Industrial equipment, old kiosks, vintage hardware projects. These are extreme edge cases. For any normal audio application (music, podcasts, voice memos, video soundtracks), use modern codecs. Don't create IMA ADPCM without specific legacy hardware requirement.
How do I extract IMA ADPCM from game files?
VGMStream is best tool for game audio extraction. Supports hundreds of game formats containing IMA ADPCM. Open game's audio files in VGMStream (or foobar2000 with VGMStream plugin), tool recognizes format and extracts/converts audio to WAV. Essential tool for game music preservation and extraction.
Game-specific extractors: Some games have dedicated community tools. Search 'game_name audio extractor' or check game modding communities. Enthusiasts often create custom extraction tools for popular games. These may handle game-specific IMA ADPCM implementations better than generic tools.
Manual extraction: If automated tools fail, analyze game files with hex editor, identify IMA ADPCM data (look for header patterns, recognizable compression patterns), manually extract bytes, decode with FFmpeg specifying raw IMA format. Advanced technique requiring format knowledge but works when other methods fail. Last resort for obscure game formats.
Does converting IMA ADPCM to MP3 make sense?
Generally not ideal: IMA ADPCM is already lossy. Converting to MP3 is lossy-to-lossy transcoding - stacking compression artifacts. Quality degrades from original. If you have IMA ADPCM source, better to convert to lossless WAV for archival, then encode MP3 from WAV if needed for distribution.
However, IMA ADPCM quality is so limited that additional MP3 compression at decent bitrate (128kbps+) doesn't hurt much. Audio quality ceiling is already low. Practical consideration: MP3 plays everywhere, IMA ADPCM has compatibility issues. Trading small quality loss for universal compatibility might be worthwhile trade-off.
Recommendation: Convert IMA ADPCM to WAV (preserves existing quality), then decide based on use case. Archive as WAV (lossless preservation). Distribute as MP3 if file size/compatibility matters. Or just distribute WAV - already limited quality, file sizes aren't huge. Choose based on actual needs, not theoretical purity.
What sample rates did IMA ADPCM use?
Common rates: 8kHz (telephony quality, voice only), 11.025kHz (quarter CD quality, voice/basic audio), 22.05kHz (half CD quality, games/multimedia), occasionally 44.1kHz (CD quality, though rare for IMA ADPCM). Higher sample rates increase file size; IMA ADPCM compression ratio stays 4:1 regardless of sample rate.
Game usage: Many 1990s games used 11kHz or 22kHz for dialogue and effects. Compromise between quality and size. 8kHz too muddy for game effects; 44.1kHz too large. 11-22kHz sweet spot for game audio on CD-ROM. Modern ears notice the bandwidth limitation - sounds dated.
Voice applications: 8kHz standard for voice prompts, narration, speech-only content. Telephone quality but intelligible. Anything higher wasted space for voice-only. Music: some multimedia apps used 22kHz or 44.1kHz IMA ADPCM for background music. Quality was poor (ADPCM not designed for music) but small file sizes allowed more music tracks on CD-ROM.
Should I preserve IMA ADPCM originals after converting?
For archival purposes: preserve originals if they're from historically significant sources (important games, multimedia titles, research datasets). Original files are authentic artifacts. Converted WAV provides access, originals provide authenticity. Storage is cheap; keeping both is reasonable.
For casual use: WAV conversion alone probably sufficient. IMA ADPCM is lossy; you're not discarding higher quality original. WAV captures everything in IMA ADPCM (after decompression). Unless files have specific historical/archival value, converted WAV serves all practical needs.
Document conversion: note tool used (FFmpeg version, SoX version), conversion date, source details. Metadata about conversion process matters for archival purposes. WAV file itself doesn't indicate it came from IMA ADPCM - documentation provides context. Good preservation practice whether keeping originals or not.