Audio Conversion for Podcasts: Choosing the Right Format for Spotify and Apple Podcasts

Podcasts have become a dominant form of content consumption, offering creators a powerful way to engage audiences worldwide. However, producing a podcast that meets platform specifications, maintains high audio quality, and is optimized for listeners’ devices requires careful consideration of audio format, bitrate, and file size.

In 2026, Spotify and Apple Podcasts remain the leading platforms for podcast distribution. Each platform has specific requirements regarding file formats, sample rates, and loudness standards. Adhering to these requirements ensures your podcast episodes are delivered with consistent quality, smooth playback, and an optimal listening experience.

Spotify and Apple Podcast Requirements

Both Spotify and Apple Podcasts maintain specific technical guidelines that producers must follow to guarantee compatibility and optimal performance across their platforms. Spotify currently accepts MP3, AAC, and Opus formats, with a recommended bitrate of 96–128 kbps for voice-centric podcasts. Additionally, the platform enforces loudness normalization to approximately -14 LUFS to ensure a consistent listening volume between different shows.

Apple Podcasts primarily supports the MP3 and AAC formats and requires episodes to use a 44.1 kHz sample rate with a bitrate between 64 and 128 kbps. Apple also emphasizes the use of consistent metadata to ensure that episode titles, artwork, and descriptions display accurately to listeners. Adhering strictly to these specifications ensures smooth ingestion, reliable playback, and better discoverability across all hardware, from smartphones to smart speakers.

MP3 vs. AAC vs. Opus

Selecting the right audio format requires balancing sound quality, file size, and universal compatibility. The MP3 remains the most widely supported format, ensuring your podcast will play on virtually any app, though it results in slightly larger files at the same level of quality. Alternatively, AAC offers superior compression efficiency compared to MP3, allowing for smaller file sizes while maintaining excellent clarity, making it the preferred choice for Apple Podcasts.

For creators looking for the cutting edge, Opus is a highly efficient modern codec that is particularly well-suited for voice content, as it can dramatically reduce file sizes. 

However, it suffers from limited compatibility with older applications. For those targeting a broad audience across both Spotify and Apple Podcasts, sticking with MP3 or AAC is generally the safest strategy, while Opus is an ideal option for platforms or custom apps that specifically support it.

You can easily convert your audio files from one file type to another with tools like this one https://documents.io/audio-converter or download specialist software if you have a lot of files. 

Bitrate Optimization

Bitrate determines the volume of data used to encode audio every second, directly influencing the balance between sound clarity and file size. While higher bitrates enhance audio detail, they also create much larger files; conversely, lower bitrates shrink the file size but can eventually degrade voice quality if pushed too far.

For professional podcasts, 64 kbps is considered acceptable for spoken word content in mono, offering the smallest possible file size. Moving up to 96–128 kbps is the industry standard for achieving clear, professional voice quality in stereo. Bitrates above 128 kbps are generally unnecessary for the podcast format, unless the show features significant musical segments or high-fidelity soundscapes. By optimizing these settings, creators ensure their episodes remain download-friendly for listeners on limited mobile data plans while still maintaining a professional level of clarity.

Mono vs. Stereo

Since most podcasts consist primarily of spoken content, mono audio is often more than sufficient for high-quality delivery. Converting a stereo recording to mono can reduce the final file size by half while perfectly preserving the clarity of the voice. This makes mono audio the ideal choice for voice-only shows, as it significantly improves download speeds and reduces bandwidth usage for listeners on mobile networks.

Stereo audio remains the better option only when a production includes music, intricate sound effects, or multi-person recordings that require spatial separation to help the listener distinguish between different speakers or elements. For the vast majority of creators, however, opting for mono ensures a lean, efficient file without sacrificing professional sound quality.

Sample Rate Selection: 44.1kHz Standard

The recommended sample rate for digitizing podcast audio is 44.1 kHz. This standard ensures compatibility with major platforms like Spotify and Apple Podcasts, as well as most other podcast applications, guaranteeing accurate playback without pitch or timing problems. Using 44.1 kHz also strikes an optimal balance between high audio fidelity and manageable file size. Higher sample rates, such as 48 kHz, are typically unnecessary for voice-focused podcasts and will only result in larger file sizes.

Metadata Embedding

Embedding comprehensive metadata (ID3 tags, chapter markers, and high-quality artwork) is essential for podcast discoverability, organization, and a professional listener experience. This includes the episode title, description, author, date, and square artwork (1400×1400 to 3000×3000 pixels). Proper metadata ensures accurate search results, makes segment navigation easier, and helps your show stand out.

Normalization and Loudness Standards (LUFS)

Consistent audio loudness is key for listener comfort and a professional image. Spotify normalizes to -14 LUFS, and Apple Podcasts also recommends consistent levels to prevent jarring volume shifts. Normalizing your audio before export prevents these abrupt changes, improving listener satisfaction and retention with a smooth, reliable experience.

Downloads and Mobile Data Usage

For podcast accessibility and completion, keep file sizes between 30–60 MB per hour, achieved with a 96–128 kbps bitrate. Use mono channels and strategic compression to reduce data footprint without sacrificing clarity. Avoid over-compression to prevent distracting audible artifacts. Optimizing file size ensures easy downloads and boosts listener engagement.

Properly optimized podcast audio improves accessibility, boosts engagement, and enhances professional presentation — critical factors for a successful podcast in 2026 and beyond. Following normalization standards and testing across apps ensures a seamless listener experience.