Last verified: 7 September 2026. Read from the Substack Team note on 2 September 2026 and Substack Help Center articles updated the same day. No affiliate links. This sits next to The Page Note Is the Offer.
Are Substack podcast analytics IAB certified? Yes. As of 2 September 2026, Substack says its podcast download measurement follows IAB Tech Lab Podcast Measurement Technical Guidelines, Version 2.2. An IAB-style download on Substack is not a play button tap. It is a filtered file request: at least one minute of audio delivered to a unique device inside a 24-hour window aligned to U.S. Pacific time. Spotify downloads now sit in the same dashboard, with up to a 24-hour lag.
That is a real operations change for anyone who sells a show from a Substack RSS feed. It is not a rate card. Certification tells a buyer the count was built to a public method. It does not tell them the audience is the same as an Apple, YouTube, or megaphone number they already trust, and it does not tell them the episode created a subscriber or a sale.
Certification is a shared ruler. It is not a shared audience, and it is not a close.
The operator line
Key takeaways
- Substack podcast downloads are IAB Tech Lab certified under Version 2.2 as of 2 September 2026.
- A counted download needs the file header plus at least 60 seconds of audio (the whole file if the episode is 60 seconds or shorter), on a unique device, once per Pacific calendar day.
- Spotify activity is now included in Substack podcast totals and can take 24 hours to appear.
- Use the certified number in the deck. Price the show on listeners, countries, players, and a next-step metric the sponsor can audit.
What Substack actually announced
The Substack Team note is two sentences of product, not a manifesto. First: download measurement is IAB Tech Lab certified, which they frame as easier sponsor pitches and cleaner growth reporting. Second: Spotify downloads are folded into Substack podcast data. They call both items the start of a larger podcasting push.
The Help Center is the document you should quote, not the note. Substack’s own definition: an IAB certified download measures how many times at least 60 seconds of an episode is downloaded to a unique device over a 24-hour period. Dashboard views still include average downloads at 7 / 30 / 90 days, daily and cumulative totals, per-episode totals, top countries, and top players. Episodes that also went out as posts can show view and open rates plus subscriptions gained after a listen.
What an IAB-certified download is
IAB Tech Lab writes the public method hosts use so a “download” is not whatever the vendor felt like counting that quarter. The current Substack implementation cites Version 2.2. IAB released Version 2.3 for public comment in July 2026; that update is not what Substack’s Help Center cites today. Do not mix the versions in a deck.
On Substack the method is server-side. Counts come from CDN access logs for audio-file requests, not from a pixel in a player chrome. Unique identity is a hash of IP address + User-Agent + episode + Pacific calendar day. Same IP and same User-Agent, same episode, same day: one download. Same IP with different User-Agents on the same day: separate downloads. IPv4 is used in full. IPv6 is truncated to the first four groups so one home network does not mint a pile of fake uniques.
Partial (HTTP 206) requests are reassembled. The download counts only after delivered bytes clear the threshold: ID3 / header bytes plus at least one minute of audio. Full episodes and free previews use separate identifiers and show as separate metrics. That last point matters if you sell a paid feed and a public tease as if they were one inventory.
What gets thrown out
Before a request becomes a download, Substack applies filters that should be in the footnote of every one-pager:
- Known data-center and cloud ranges from AWS EC2, Google Cloud, Azure, Oracle Cloud, and DigitalOcean, refreshed daily.
- IAB Tech Lab Spiders & Robots and Valid Browsers lists, synced daily. Bot user-agents do not count.
- Any single IP that generates more than 1,000 downloads in a day is treated as anomalous and excluded.
If you embed the player, do not autoplay unless the listener asked. That is Substack’s own note, and it is also how you avoid arguing with a buyer about inflated first-paint requests.
What Spotify in the dashboard changes
For a long stretch, a Substack host could tell a sponsor “the RSS number” and then watch Spotify sit in another product with another clock. That split is the thing that made mid-size shows look smaller than they were, or larger than they could defend, depending on which screenshot they pasted.
Spotify downloads now flow into the Substack podcast totals. Expect a one-day lag. Paid Substack shows can also distribute through Spotify Open Access: discoverable on Spotify, existing subscribers can listen there, free listeners get an upgrade path. Founding-member episodes and free previews of paid episodes are still not in that Spotify sync. If those SKUs are how you make money, say so in the deck instead of letting a buyer assume the Spotify graph is the whole show.
Spotify for Podcasters remains a second surface. Claim the show there if you need streams, unique listeners, play time, and demographics. Do not paste the two dashboards into one cell and call it IAB.
| Number | What it is | Put it in a sponsor deck? |
|---|---|---|
| Substack IAB downloads | Filtered CDN requests under v2.2, including Spotify after the lag | Yes — as the certified download line |
| 7 / 30 / 90-day averages | How an episode ages after publish | Yes — shows whether the catalog works |
| Top countries and players | Where and in which apps the files land | Yes — geo and device context |
| Subscriptions after a listen | Substack’s own next-step metric | Yes — if the buyer cares about owned audience |
| Spotify streams / play time | Platform-native listening, not the IAB download definition | Yes — labeled as Spotify, never summed into IAB |
| YouTube views on a video episode | A different product event | Separate line or leave it out |
How to write the sponsor one-pager now
The certification is useful because it removes a cheap objection: “your host invents downloads.” Replace that slide with four lines a media buyer can check without a call.
- Method. “Downloads follow IAB Tech Lab Podcast Measurement Technical Guidelines v2.2, measured by Substack from CDN logs.” Link the Help Center article. Do not write “IAB certified” with no version.
- Window. “Unique device, 60-second minimum, Pacific calendar day, bots and cloud ranges excluded.”
- Scope. “Includes Spotify with a 24-hour lag. Does not include YouTube. Paid founding episodes are not in the Spotify Open Access sync.”
- Proof of value. One next-step number you own: trial starts, paid conversions after the episode, booked calls, or reply rate to the show email. Downloads are the reach line. This is the reason to buy.
If you cannot fill line four, you do not have a sponsorship product. You have a certified vanity metric. The same rule we use on page notes applies here: the asset can travel; the claim has to live on ground you can show.
What not to claim
Do not tell a buyer your IAB number is comparable to another host’s IAB number without saying the remaining gaps. Different CDNs, different bot lists, different treatment of video podcasts, different handling of previews, and different Spotify contracts still move the total. Certification shrinks the argument. It does not end it.
Do not treat a download as a completed listen. The threshold is one minute, not the episode. A 42-minute interview that clears 60 seconds is a download. It is not proof the mid-roll landed.
Do not hide the Pacific-time window. A late evening publish on the East Coast can split early listening across two Substack days. If you report “day-one downloads,” say which clock you mean.
FAQ
Are Substack podcast analytics IAB certified?
Yes. Substack updated its Help Center on 2 September 2026 to say downloads now follow IAB Tech Lab industry standards, implemented against Version 2.2 of the Podcast Measurement Technical Guidelines.
What counts as an IAB-certified download on Substack?
At least 60 seconds of the episode delivered to a unique device in a 24-hour period. Substack identifies the device by hashing IP, User-Agent, episode, and the Pacific calendar day. Short episodes at or under 60 seconds must be delivered in full.
Does the Substack download number include Spotify?
Yes. Spotify downloads are included in Substack podcast data and can take up to 24 hours to appear. That is separate from Spotify-native stream and play-time stats inside Spotify for Podcasters.
Can I sell IAB downloads as completed listens?
No. The certified unit is a qualified file request, not a finish rate. If a buyer needs completion or average consumption, that is a different report — and on Spotify it lives in a different dashboard.
Does IAB certification set my CPM?
No. Certification is the measurement language. Price still comes from who is listening, whether they take a next step you can show, and how scarce that inventory is in the buyer’s category.
What to do this week
- Open the Substack Podcasts dashboard. Export 7 / 30 / 90-day averages and top countries / players for the last eight episodes.
- Rewrite the measurement footnote on the one-pager to name IAB Tech Lab v2.2, the 60-second rule, the Pacific day, and the Spotify lag.
- Add one owned next-step column. If you cannot name it, you are not ready to send the deck.
- If the show is paid, confirm whether Spotify Open Access is on, and state what is excluded (founding episodes, paid previews).
- Stop summing YouTube, Spotify streams, and IAB downloads into one “listens” cell.
Close
Substack gave operators a ruler sponsors already recognize, and it stopped leaving Spotify in a side drawer. That is enough to update the footnote. It is not enough to raise the rate.
Sell the certified download as reach. Sell the next step as the product. Keep the two lines from collapsing into each other.
Sources
- Substack Team note on IAB certification and Spotify downloads
- Substack Help: Are Substack podcast analytics IAB certified?
- Substack Help: Understanding your Substack Podcast dashboard
- Substack Help: Paid podcasts on Spotify
- IAB Tech Lab podcast measurement guidelines
Will Tygart — Tygart Media. Written 7 September 2026 from the Command Center. Measurement details above are from Substack and IAB Tech Lab public documents, not an audit of Substack’s production logs.
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