Delivering Audio for Netflix, Amazon, and Apple TV Plus: The Spec Differences That Matter
The QC Rejection Nobody Saw Coming
Your film passed picture QC on its first submission. Two days later, the audio QC report came back with four items: integrated loudness at -22.8 LUFS instead of the required -24.0, a true peak event exceeding -1.0 dBTP at 01:14:22, the 5.1 mix flagged for LFE channel imbalance, and the stereo downmix absent from the delivery package entirely.
The distributor gives you 10 business days to resubmit. You need to go back to your mix engineer, regenerate the audio files, repackage the delivery, and resubmit -- all at a cost you had not budgeted for and on a timeline that delays your launch.
Each major streaming platform has specific, documented audio delivery requirements. Meeting them on the first submission is not difficult. Not knowing them is.
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
| Specification | Netflix | Amazon Prime Video | Apple TV Plus |
|---|---|---|---|
| Integrated loudness target | -27 LUFS | -24 LUFS | -24 LUFS |
| Tolerance | +/- 2 LU | +/- 2 LU | +/- 2 LU |
| True peak maximum | -2.0 dBTP | -2.0 dBTP | -1.0 dBTP |
| Stereo downmix required | Yes (Lt/Rt) | Yes | Yes |
| Preferred surround format | 5.1 or Atmos | 5.1, 7.1, or Atmos | 5.1 or Atmos |
| Preferred codec (master) | PCM / IMF | PCM (WAV) | PCM (WAV) |
| Sample rate | 48kHz | 48kHz | 48kHz |
| Bit depth | 24-bit | 24-bit | 24-bit |
| Atmos accepted | Yes (ADM BWF) | Yes (IAB) | Yes (strongly preferred) |
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
- 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.
- 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.
- 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.
- 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.
- 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.
- 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 You Deliver
Netflix, Amazon, and Apple TV Plus each have specific, documented audio delivery requirements. The differences between them -- particularly Netflix's quieter -27 LUFS target and Apple's stricter -1.0 dBTP true peak limit -- are the source of most audio QC rejections on first delivery. Verify your audio against the specific platform spec before submission and run a QC check on the final delivery files. A QC rejection is always a more expensive problem to fix after delivery than before it.
What audio QC issue have you encountered on a platform delivery that was not on your pre-delivery checklist?
