Audio ad specs differ by platform. Spotify takes ads up to 30 seconds as MP3, WAV or OGG at −16 LUFS. YouTube audio ads run up to 30 seconds and are uploaded as a video. Amazon takes 10 to 30 seconds, and SiriusXM takes 30- and 60-second spots. The table below has every number, checked on 13 October 2026.
Key Takeaways
- Length: 30 seconds is the one length every platform here accepts. Spotify music ads and Amazon audio ads stop at 30 seconds.
- Loudness is not one number. Spotify asks for −16 LUFS (±1.5), Amazon for RMS −14 dBFS, and SiriusXM for a −5 dB limiter ceiling.
- Word count: Spotify recommends no more than 65 words for 30 seconds. Google suggests 60–80 words for a 30-second YouTube audio ad.
- Files: Spotify and SiriusXM ask for 44.1 kHz. A WAV master lets you export each platform’s version without re-recording.
- UK radio: ads in special categories, such as alcohol, gambling and financial products, must be cleared by Radiocentre before broadcast.
Audio ad specs by platform: the master table
Each row comes from the platform’s own spec page, retrieved 13 October 2026. A dash means the page does not state a value, so check with your account rep.
| Platform | Lengths | File types | Bitrate and sample rate | Loudness | Max file size |
|---|---|---|---|---|---|
| Spotify (music ads) | Up to 30 s; up to 60 s long-form in select markets (Direct only) | MP3, WAV, OGG | 192–320 kbps, 44.1 kHz, stereo | −16 LUFS, ±1.5 LUFS | 50 MB |
| Spotify (podcast ads, streaming ad insertion) | Up to 30 s | MP3, WAV, OGG | 192–320 kbps, 44.1 kHz, stereo | −16 LUFS, ±1.5 LUFS | 50 MB |
| YouTube audio ads | Up to 30 s (≤ 15 s non-skippable, 16–30 s skippable) | A YouTube video link, 16:9 | – | – | – |
| Amazon Ads audio ads | 10–30 s (any length in between) | WAV, MP3, OGG | At least 192 kbps | RMS −14 dBFS, peak −0.2 dBFS | 3 MB |
| SiriusXM audio spots | 30 s and 60 s (15 s on the Weather channel only) | MP3 or 16-bit WAV | At least 320 kbps, 44.1 kHz | Limiter ceiling −5 dB (−8 dB for mono) | – |
| Apple Podcasts (the episode a host-read ad sits in) | Not limited | AAC (recommended) or MP3 | 128–256 kbps stereo at 44.1/48 kHz | −16 LKFS ±1 dB, true peak ≤ −1 dBFS | – |
Amazon’s page lists “at least 192 kbps” on the same line as its loudness target. We read it as the bitrate minimum.
Spec details and export checklists for each platform
Pick a platform to see its full spec, its script limits and a checklist you can copy into your brief or your editor notes.
Spotify audio ad specs
Audio: music ads and podcast ads run up to 30 seconds. Long-form music ads can run up to 60 seconds in select markets for Direct campaigns and are skippable after 30 seconds. Upload MP3, WAV or OGG, 44.1 kHz, stereo, 192–320 kbps, up to 50 MB, at −16 LUFS (±1.5 LUFS).
Script: Spotify recommends no more than 65 words for a 30-second ad and 100 words for a 60-second ad. A podcast ad’s spoken call to action should match the campaign’s call to action.
Around the audio: one companion image is required (1:1, at least 600 × 600 px, JPEG or PNG, up to 200 KB). The advertiser name is up to 25 characters and the tagline up to 40.
Spotify export checklist Brief
Need the voice too? See AI voiceovers for Spotify ads.
YouTube audio ad specs
Audio: YouTube audio ads run up to 30 seconds. Ads up to 15 seconds play as non-skippable, and ads of 16 to 30 seconds play as skippable. They serve on audio surfaces and in listening-first moments on YouTube and YouTube Music.
File: you don’t upload an audio file. You upload a video to YouTube and give Google Ads its link. Use 16:9; a 4:3 file gets black bars. Google suggests a still image or a simple animation as the picture.
Script: Google suggests 60–80 words of voiceover for a 30-second ad, plus a clear next step, such as a short web address read aloud or shown on screen.
YouTube audio ad checklist Brief
Amazon Ads audio ad specs
Audio: 10 to 30 seconds, any length in between. WAV, MP3 or OGG, up to 3 MB, at least 192 kbps, RMS normalized to −14 dBFS and peak normalized to −0.2 dBFS. Ads that may run on Twitch must be 12–15 or 27–30 seconds long.
Voice: Amazon says every voiceover must be easy to hear and understand, with even pacing. Disclaimers must be read at roughly the same volume and pace as the rest of the ad, so don’t speed up the small print.
Around the audio: a 1024 × 1024 px companion image is required (a 300 × 250 px one is optional), JPEG or PNG, up to 750 KB. The headline is up to 19 characters.
Amazon audio ad checklist Brief
SiriusXM audio spot specs
Audio: SiriusXM accepts pre-produced 30- and 60-second spots. 15-second ads run only on its Weather channel. Deliver MP3 or 16-bit WAV at 44.1 kHz and at least 320 kbps. Master with a limiter ceiling of −5 dB, or −8 dB for mono.
Script: SiriusXM suggests a natural, conversational voiceover that names the problem, offers the answer and ends with a strong call to action.
SiriusXM spot checklist Brief
Podcast ad specs
Inserted ads: if you buy podcast ads through Spotify’s streaming ad insertion, the Spotify specs apply: up to 30 seconds, −16 LUFS. Other podcast networks set their own specs, so ask the host or network for theirs.
Host-read or baked-in ads: the ad becomes part of the episode, so it should match the episode. Apple Podcasts asks for about −16 LKFS (±1 dB) with true peak no higher than −1 dBFS. It recommends AAC over MP3, at 128–256 kbps for stereo at 44.1 or 48 kHz.
Podcast ad checklist Brief
If the ad uses an AI voice, check the platform’s labelling rules with our AI voice disclosure generator.
UK radio ad clearance
Clearance: Radiocentre checks UK commercial radio ads against the BCAP Code and the Ofcom Broadcasting Code. Ads for special-category advertisers must be cleared before broadcast. These include gambling, alcohol, financial products, medical and health products, food supplements, dating services, charities and religious groups.
Timing: Radiocentre aims to clear or advise on a script within 24 hours of upload during office hours. A 2-hour Fast Track costs £300 plus VAT per script for non-members, or £100 plus VAT for full members.
Files: technical delivery specs are set by each station group, so ask the sales house for its sheet before you master.
UK radio ad checklist Brief
Specs sorted? Paste your ad script into Kveeky, pick a voice and download a WAV master to mix and export for each platform.
Voice your ad freeWill your script fit? Check it against the platform’s word guidance
Paste your ad script and pick a pace. The presets turn each platform’s published word guidance into a reading speed. Set the target to your ad length to see your word budget.
For longer scripts and more paces, use the full words to minutes calculator.
| Ad length | Spotify guidance | YouTube guidance | Average speech (150 wpm) |
|---|---|---|---|
| 15 seconds | – | – | About 38 words |
| 30 seconds | 65 words or fewer | 60–80 words | About 75 words |
| 60 seconds | About 100 words | – (YouTube audio ads stop at 30 s) | About 150 words |
The average-speech column uses the 150 words per minute rate from the National Center for Voice and Speech. Platform columns show only what each platform publishes.
How to make one master that fits every platform
- Write to the strictest word budget. 65 words for 30 seconds fits both Spotify and YouTube guidance.
- Voice the script once and download a WAV, so later exports don't stack compression on compression.
- Mix voice and music in your editor, and read disclaimers at the same pace as the rest of the ad.
- Export one version per platform: −16 LUFS for Spotify, RMS −14 dBFS for Amazon, a −5 dB ceiling at 320 kbps for SiriusXM.
- Measure before you upload. Check length, loudness and file size against the table, then upload.
Loudness targets are measured on the finished mix, so set them after the music goes in. Our guide to pauses, emphasis and pacing helps a short read sound unhurried.
How Kveeky helps you produce audio ads
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Do these loudness rules apply to TV ads too?
No, TV has its own rule. In the US, the CALM Act rules require TV broadcast stations to follow the ATSC A/85 Recommended Practice for commercial loudness, effective 13 December 2012. That rule covers television, not streaming audio, so use the platform figures above for audio ads.
Before you upload: audio ad checklist
| Check | Why it matters |
|---|---|
| Length matches an accepted slot | Spotify and Amazon stop at 30 s; SiriusXM takes 30 s or 60 s |
| Word count fits the platform’s guidance | Rushed reads lose listeners; Spotify suggests 65 words or fewer for 30 s |
| Loudness measured on the final mix | Each platform states its target differently (LUFS, RMS or limiter ceiling) |
| File type, bitrate and sample rate match | Spotify wants 192–320 kbps at 44.1 kHz; SiriusXM at least 320 kbps |
| File is under the size limit | Amazon’s limit is 3 MB, much lower than Spotify’s 50 MB |
| Companion image and headline ready | Spotify and Amazon both require a companion image |
| UK special-category ads cleared | Radiocentre must approve them before broadcast |
| Audio made on a paid plan if it promotes a business | Paid Kveeky plans include commercial usage rights |
Frequently asked questions
What are the specs for a Spotify audio ad?
Up to 30 seconds, as MP3, WAV or OGG, 44.1 kHz stereo at 192–320 kbps, up to 50 MB and −16 LUFS (±1.5). Long-form ads up to 60 seconds are available only in select markets for Direct campaigns.
How many words should a 30-second audio ad be?
Spotify recommends no more than 65 words for 30 seconds. Google suggests 60–80 words for a 30-second YouTube audio ad.
How long can a YouTube audio ad be?
Up to 30 seconds. Ads up to 15 seconds play as non-skippable, and ads of 16 to 30 seconds play as skippable.
What loudness should an audio ad be?
It depends on the platform. Spotify asks for −16 LUFS (±1.5), Amazon for RMS −14 dBFS with peaks at −0.2 dBFS, and SiriusXM for a −5 dB limiter ceiling.
What file format should I use for audio ads?
MP3 and WAV are accepted by Spotify, Amazon and SiriusXM. YouTube audio ads are uploaded as a video instead.
Do UK radio ads need approval before they air?
Ads for special categories, such as gambling, alcohol and financial products, must be cleared by Radiocentre before broadcast. It aims to respond within 24 office hours.
Sources
- Spotify lengths, file types, bitrate, sample rate, loudness, file size, word counts and companion specs: Spotify Advertising, “Audio ad specs”, retrieved 13 October 2026.
- YouTube audio ad length, skippable rule, video link, 16:9 and the 60–80 word guidance: Google Ads Help, “Create YouTube audio ads”, retrieved 13 October 2026.
- Amazon audio ad length, file types, size, volume, Twitch durations, companion image, headline and voiceover rules: Amazon Ads, “Audio ads” ad specs, retrieved 13 October 2026.
- SiriusXM spot lengths, file format, bitrate, sample rate and limiter ceiling: SiriusXM Media, “Audio spots”, retrieved 13 October 2026.
- Podcast loudness, true peak, formats and bitrates: Apple Podcasts for Creators, “Audio requirements”, retrieved 13 October 2026.
- UK radio clearance categories, turnaround and Fast Track fees: Radiocentre, “Clearance”, retrieved 13 October 2026.
- US TV commercial loudness rule: eCFR, 47 CFR 73.682(e), retrieved 13 October 2026.
- Average speaking rate of about 150 words per minute: National Center for Voice and Speech, “Voice Qualities”, retrieved 13 October 2026.
- Kveeky formats and plan rights: Kveeky pricing, retrieved 13 October 2026.