Delivering Audio for Netflix, Amazon, and Apple TV Plus: The Spec Differences That Matter

The QC Rejection That Cost 10 Business Days and a Delayed Launch

The picture QC passed on first submission. Two days later, the audio report comes back with four flags: integrated loudness measured at -22.8 LUFS against a -24.0 LUFS target, a true peak event at 01:14:22 exceeding -1.0 dBTP, the 5.1 mix flagged for LFE channel imbalance, and the stereo downmix absent from the delivery package entirely.

The distributor gives 10 business days to resubmit. The mix engineer's schedule requires five of them. The delivery delay pushes the platform launch date, and the aggregator charges a redelivery fee. The total cost in engineering time, aggregator fees, and launch delay is several thousand dollars. None of it was in the post-production budget.

Every major streaming platform publishes specific, documented audio delivery requirements. Meeting them on first submission requires knowing what those specifications are before the final mix session begins, not after the QC report arrives. This post covers the spec differences between Netflix, Amazon Prime Video, and Apple TV Plus that cause the most rejections, with the measurement standards and delivery checklist to use before submission.

All loudness specifications in this post reference the ITU-R BS.1770-4 integrated loudness measurement standard, which underpins every major platform's audio spec. The European Broadcasting Union's EBU R128 specification, which preceded BS.1770-4 and established the LUFS metering framework used industry-wide, provides the technical foundation for understanding why these targets are set where they are.

How Streaming Platform Audio Specs Work

Every major streaming platform publishes a delivery specification document -- sometimes called a delivery requirements guide, an IMF spec, or a technical partner guide. These documents specify the exact loudness target, peak level limit, channel configuration, codec, and container format required for audio delivery.

When your audio delivery does not meet these specifications, the platform's automated or manual QC system flags the non-conforming items. Repeated QC failures can delay release, incur redelivery fees through your aggregator or distributor, and in some cases trigger penalty clauses in your distribution agreement.

The key loudness standard underlying all major platform specs is the ITU-R BS.1770-4 integrated loudness measurement system, which uses the LUFS (Loudness Units relative to Full Scale) metric. For the complete explanation of LUFS and how to measure and correct your film's loudness, use the LUFS Calculator alongside this guide.

Netflix, Amazon, and Apple TV Plus Audio Specs Compared

Netflix (as of early 2026):

Netflix accepts delivery through their Backlot portal and through approved post-production facilities. Netflix strongly prefers IMF (Interoperable Master Format) delivery for features.

Loudness: -27 LUFS integrated (programme loudness) is Netflix's primary target for long-form content, with a tolerance of +/- 2 LU. True peak maximum: -2.0 dBTP. Netflix's loudness specification is notably quieter than other major platforms, which frequently catches audio teams expecting the more common -24 LUFS standard.

Dialogue Intelligence (DI) flag: Netflix requires a content flag indicating whether Dialogue Intelligence normalisation is applied. For content delivered at -27 LUFS without DI, the flag should be set to "False."

Channel formats accepted: Mono (1.0), Stereo (2.0), 5.1 surround, Atmos (immersive audio). Netflix requires a separate stereo Lt/Rt downmix alongside any surround or Atmos delivery. For Atmos content, Netflix accepts ADM BWF (Broadcast Wav Format) or Dolby Atmos Master files via their IMF workflow.

Amazon Prime Video (as of early 2026):

Amazon's delivery specs are documented in their Prime Video Direct and Amazon Studios delivery specifications.

Loudness: -24 LUFS integrated is Amazon's primary target, with a maximum true peak of -2.0 dBTP. Amazon applies loudness normalisation on playback, so content delivered above -24 LUFS will be turned down. Content delivered significantly above target (above -18 LUFS) may be flagged for correction.

Channel formats: Mono, stereo, 5.1, 7.1, and Atmos. Amazon requires a stereo downmix alongside any surround delivery. For Atmos, Amazon accepts Dolby Atmos files via their IAB (Immersive Audio Bitstream) workflow.

Codec: PCM (uncompressed WAV) is preferred for master delivery. Amazon also accepts Dolby Digital and AAC for lower-tier deliveries, but PCM is required for original content and prestige acquisitions.

Apple TV Plus (as of early 2026):

Apple's audio delivery requirements are documented in their Apple Video Partner Hub delivery specifications.

Loudness: -24 LUFS integrated, true peak maximum -1.0 dBTP. Apple's true peak limit of -1.0 dBTP is tighter than Netflix and Amazon's -2.0 dBTP limit and is the most common source of Apple-specific QC rejections.

Channel formats: Stereo, 5.1, and Atmos. Apple strongly prefers Atmos for original content and has made Atmos a de facto requirement for Apple Original Films. For non-original licensed content, 5.1 with a stereo downmix is acceptable.

Codec: Apple ProRes audio (PCM wrapped in ProRes container) is preferred for picture-locked deliveries. For audio-only stems and mixes, 24-bit PCM WAV at 48kHz is required.

Audio Specification Comparison Table

Specifications are subject to change. Always verify against the platform's current delivery specifications document before final delivery.

How to Prepare Your Audio Delivery for Multiple Platforms: Step by Step

1. Determine which platforms you are delivering to before your final mix. Different loudness targets require different mix approaches. A mix optimised for Apple TV Plus at -24 LUFS will not meet Netflix's -27 LUFS target without re-processing. If you are delivering to multiple platforms, produce a single master mix at the most conservative spec (-27 LUFS for Netflix) and normalise up for platforms that accept -24 LUFS.

1. Measure integrated loudness with a broadcast-compliant loudness meter. Free and paid plugins (iZotope Insight, Nugen VisLM, Waves WLM Plus) measure ITU-R BS.1770-4 integrated loudness. The LUFS Calculator can help you calculate the gain adjustment needed to hit a target loudness from your current measurement. Do not rely on your DAW's peak metering -- it does not measure integrated loudness per the ITU standard.

1. Check true peak levels at full mix and on each stem. True peak is the reconstructed inter-sample peak level, not the sample peak. A waveform that reads -2.5 dBFS on sample peak can exceed -1.0 dBTP on true peak. Use a true peak limiter (Fabfilter Pro-L 2 in true peak mode, or Waves L3 Ultramaximizer) on your master bus and verify the output is within the target platform's limit.

1. Generate the stereo downmix and verify it independently. A stereo downmix generated automatically from a 5.1 mix by your DAW may have phase problems, centre channel imbalance, or LFE content that causes clipping. Generate the Lt/Rt downmix and check it for loudness, peak levels, and audible problems as a separate deliverable.

1. Prepare the delivery package per platform specifications. Netflix delivery via Backlot requires specific file naming conventions and checksums. Amazon delivery through Prime Video Direct requires files in a specific folder structure. Apple delivery through Apple Video Partner Hub requires Apple-specific metadata. Your aggregator or distributor will typically handle packaging -- but verifying the audio specs before delivery reaches them prevents a bounce-back from the platform's QC.

1. Run a QC check on your final delivery files. Software tools (Mediainfo, Resolve's built-in inspector, or dedicated QC tools like Vidchecker) can verify loudness, peak levels, sample rate, bit depth, and channel configuration before you submit. A 20-minute QC check before submission can prevent a 10-business-day delay after rejection.

Pro Tips and Common Mistakes

Pro Tip: Netflix's -27 LUFS target is the most common cause of audio QC rejection for films previously mixed for theatrical release at -24 LUFS or for broadcast at -23 LUFS. If you are repurposing a theatrical mix for Netflix delivery, your mix engineer needs to either re-mix for the lower target or apply transparent loudness processing to the final mix. Simply normalising down from -24 to -27 often changes the dynamic feel of the mix in ways that require a real mix revision to correct properly.

Pro Tip: Apple's -1.0 dBTP true peak limit catches content that passes other platforms' -2.0 dBTP limit. Run a true peak check specifically against the Apple threshold before considering the audio delivery complete. A single true peak event at -1.2 dBTP is enough to fail Apple's QC.

Common Mistake: Delivering audio at 44.1kHz sample rate rather than 48kHz. Broadcast and streaming delivery is standardised at 48kHz. Music mixed for streaming audio (Spotify, Apple Music) at 44.1kHz is sometimes inadvertently used in film delivery packages. Always verify sample rate before delivery.

Common Mistake: Submitting a 5.1 mix without a stereo downmix. All three major platforms require a stereo mix alongside surround delivery, and they verify its presence independently. A delivery package that contains only the 5.1 mix will fail QC on this requirement alone.

Frequently Asked Questions

What happens if I deliver at -24 LUFS to Netflix instead of -27 LUFS?

Netflix's playback system applies loudness normalisation before streaming. Content delivered at -24 LUFS will be turned down 3 LU to reach the playback target. The audible difference is negligible for content listeners. However, your delivery will be flagged as non-conforming during QC and you may be required to resubmit at the correct level before release is approved.

Does Dolby Atmos delivery require a different loudness target?

Yes. Dolby Atmos content has its own loudness specification because immersive audio handles dynamics differently from channel-based audio. Atmos deliveries to Netflix target -27 LUFS for the rendering bed element, with Atmos object levels governed by the Atmos authoring session settings rather than a post-processing loudness target. For Atmos delivery to Apple, the immersive audio element should be authored to Apple's Atmos specification in Dolby Atmos Renderer.

Can I use MP3 or AAC audio for streaming delivery?

AAC is accepted by Amazon for some delivery types, but PCM (uncompressed WAV) is required for master deliveries and is strongly preferred by all three platforms for original and acquired content. MP3 is not an acceptable delivery format for any of the three platforms discussed. AAC at 256kbps or higher may be accepted for specific delivery tiers but should not be used for primary master delivery.

What is a stereo Lt/Rt downmix and how does it differ from a standard stereo mix?

A Lt/Rt (Left total / Right total) downmix is a matrix-encoded stereo version of a surround mix, designed to decode back to a surround field on Dolby Pro Logic playback devices. A standard Lo/Ro (Left only / Right only) downmix is a simple fold-down of the surround channels into left and right without matrix encoding. Most platforms accept either format for the stereo downmix requirement, but Netflix specifically requests the Lt/Rt format for content with a surround mix. Your mixing software will label the downmix output accordingly.

Related Tools and Posts

The LUFS Calculator measures your current loudness against platform targets and calculates the exact gain adjustment needed to reach the specification -- use it during the mix and again as a delivery check. For the channel format decision that precedes delivery (whether to mix in 5.1, stereo, or pursue an Atmos mix), Mono vs. Stereo vs. 5.1 vs. Atmos: Which Audio Format Does Your Film Actually Need? covers the decision framework. For the sample rate and bit depth specifications that form the foundation of your audio delivery chain, Sample Rates: 48kHz vs 96kHz for Film Production covers the technical background.

Know the Spec Before the Final Mix Session, Not After QC

Netflix, Amazon, and Apple TV Plus each have specific audio delivery requirements, and the differences between them are the source of the majority of first-submission audio rejections. Netflix's -27 LUFS integrated target is the single most common catch for films previously mixed for theatrical or broadcast at -24 LUFS. Apple's -1.0 dBTP true peak limit catches content that passed the other platforms' -2.0 dBTP threshold. The stereo downmix requirement trips up productions that deliver only a surround mix without verifying that a stereo fold-down was included.

All three issues are predictable, measurable, and fixable before the delivery package leaves your hands. Run the platform-specific loudness and peak check before the final mix session is called off and the mix engineer's setup is struck. A 20-minute QC pass at that point costs nothing. A re-booking of the mix suite costs significantly more.

This post covers the three major platforms. Hulu, Disney Plus, and international broadcasters each have separate specifications that follow the same ITU-R BS.1770-4 measurement framework but with different target values.

What audio QC issue on a delivery caught you after you thought the post workflow was complete?