Non-EU vendorCMSHeadquarters: US

Substack: sovereignty score and 8 European alternatives

Substack is a publishing platform where writers, creators and media companies publish content and earn income from paid subscriptions. The platform includes a built-in editor, support for podcasts, live video and subscriber chat, and features for comments and moderation. It offers tools for welcome sequences, win-back campaigns and analytics, and discovery runs through recommendations and Notes within the network. The service is hosted SaaS: content lives on Substack's infrastructure.

Substack, Inc. is a US company with a mailing address in San Francisco. According to its privacy policy, Substack uses service providers in the United States and other countries, and no EU region is mentioned. Substack participates in the EU-US Data Privacy Framework and its Swiss and UK extensions, and names a representative for the EEA. The policy applies only where Substack itself is the controller. For a European organisation, US jurisdiction and dependence on a single hosted platform are relevant factors.

See the 8 European alternatives ↓Assess your stack with Substack pre-selected

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Sovereignty score

17 / 1000 = high exposure
100 = sovereign

Jurisdiction SOV-210
Headquartered in the US: CLOUD Act and FISA 702
Data residency SOV-30
No hosting in Europe (US)
Cryptographic key sovereignty SOV-320
Key management with a non-European vendor
Freedom from lock-in SOV-640
Closed source: switching requires data migration
Source & runtime sovereignty SOV-4 · SOV-615
Closed source, runtime with the vendor

SOV codes: the matching objective in the European Commission's Cloud Sovereignty Framework. Official source

How the score is calculated

Facts and evidence

Last checked October 11, 2026

Headquarters	US (US)Verified by hand
EU adequacy decision	Only for companies individually certified under the EU-US Data Privacy FrameworkVerified by hand
Sovereignty model	Vendor-hosted (non-EU)Verified by hand
Data hosting	USVerified by hand
Open-source	NoVerified by hand
GDPR-compliant	YesVendor-stated
Category	CMS
Type	Product
Website	substack.com ↗

How we verify · Something wrong? Suggest a correction

Top EU-based & GDPR-compliant alternatives to Substack

The European alternatives to Substack come from our knowledge base of over 8,000 vendors. We only list vendors headquartered in the EU or the EEA; fully European-owned vendors rank before vendors with a foreign owner. For each alternative you see the country, the open-source status and a short description.

Score per alternative: 0 = high exposure, 100 = sovereign

43 European CMS vendors are in the catalogue. View the whole category · Submit an alternative · View category on the map

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Why digital sovereignty matters with Substack

Substack is headquartered in the United States. US vendors fall under the CLOUD Act and FISA 702: US authorities can compel access to data, even when that data sits in a European data centre. That is the core of the jurisdictional exposure in our model.

Substack hosts data outside the EU (US). Personal data therefore leaves the EU, which requires a transfer mechanism under the GDPR and pulls the data residency score down.

Substack is closed source and hosted by the vendor. The encryption keys and the runtime sit with the vendor and switching requires data migration. Ask about bring-your-own-key, export options and open standards.

What this means for your organisation depends on your whole stack and context. The free assessment weighs Substack together with your other vendors and gives a total score, a heatmap and the main risk drivers.

Frequently asked questions

What is the best European alternative to Substack?

It depends on your use case. Strong EU alternatives to Substack include Ametys, Bolt CMS and caisy. On this page you can compare 8 EU alternatives by jurisdiction, data residency and open-source status.

Are there open-source alternatives to Substack?

Yes. Open-source EU alternatives to Substack include Ametys, Bolt CMS, Cockpit CMS, Contao and django CMS. These keep your data fully under your own control and let you self-host if you want to.

Is Substack GDPR-compliant and where is the data hosted?

Substack is headquartered in US and hosts data in US. The vendor states it is GDPR-compliant, but the data falls under non-EU jurisdiction. For full EU data residency the EU alternatives on this page usually offer more certainty.

Details and sources

Verified by handHeadquarters, owner, hosting locations and licence have been checked by us against public sources. Free of charge and for every vendor, not a paid label. Nothing in this knowledge base is taken over automatically. Last checked on October 11, 2026.

Sources

Public sources used in the latest check of this record.

Compliance evidence

The links below point to the vendor's own public documents. We only record what we found: a missing link means "not found publicly", not "not compliant".

No public compliance evidence has been recorded for this vendor yet. Do you know its DPA or subprocessor list? Something wrong? Suggest a correction

Cyber Resilience Act

Public signals that relate to the EU Cyber Resilience Act. They do not count towards the score. A missing line means "not found publicly".

We found none of these signals on the vendor's own site when we checked.

For products in scope of the CRA, CE marking is required from 11 December 2027; this cannot be checked yet.

Checked on October 11, 2026. What is the Cyber Resilience Act?

Digital sovereignty in CMS

CMS: Content management systems — websites, headless CMS, digital experience platforms. In this category the choice of vendor determines who has legal access to your data, where that data lives and how easily you can switch later.

Also in this category

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