GuidesHulu

Hulu Delivery Guide

StreamingMost lenient SVOD

Hulu has the lowest technical bar of the major SVOD platforms — H.264 is accepted, SRT captions work, HDR is optional. But black bars and dual mono are instant rejections.

Key Rejection Causes

Black bars = hard rejection

✓ Pipewright

Hulu rejects any file with letterboxing or pillarboxing. 4:3 content in a 16:9 frame with black bars will fail. Content must be clean 16:9 or original AR without bars.

Dual mono instead of stereo

✓ Pipewright

Audio channels L+R that are identical (dual mono) are detected and flagged. Must be true stereo with distinct L and R channels, properly labeled in the container.

Separate SDH + subtitle files required

✓ Pipewright

Hulu requires SDH (Subtitles for the Deaf and Hard of Hearing) and regular subtitle files delivered as separate assets. Combining them in one file causes rejection.

SRT must be UTF-8 encoded

✓ Pipewright

Hulu accepts SRT but requires UTF-8 encoding. Windows-default ANSI encoding with special characters (em dashes, smart quotes, accented characters) fails silently.

CALM Act loudness compliance for broadcast simulcast

✓ Pipewright

Hulu is partially owned by Disney/ABC. Content intended for broadcast simulcast must comply with CALM Act: -24 LUFS integrated. Streaming-only content has more tolerance.

Hulu vs Netflix: Key Differences
Loudness methodIntegrated LUFS (not dialogue-gated)Dialogue-gated
Loudness target-24 LUFS ±2-27 LKFS ±2
CodecH.264 or ProRes 422 HQJPEG 2000 (IMF required)
CaptionsSRT acceptedTTML only
IMFNot requiredRequired for originals
HDROptionalPreferred (DV)
AtmosNot requiredPreferred for originals
Video
Resolution
1920×1080 minimum
Codec
ProRes 422 HQ or H.264
Container
.mov or .mp4
Frame rates
23.976 / 24 / 25 / 29.97
Color space
Rec.709
HDR
HDR10 optional
Black bars
Hard rejection
Interlacing
Progressive only
Audio
Loudness
-24 LUFS integrated
Tolerance
±2 LU
True Peak
-2 dBTP max
Format
PCM 24-bit or AAC-LC
Sample rate
48 kHz
Dual mono
Rejection
Atmos
Not required
Captions
Format
SRT, SCC, or TTML
Encoding
UTF-8 required
SDH
Separate file required
Burned-in
Hard rejection
Max chars/line
32 (stricter than Netflix)