X

microblogging · live · since 2006

People publish short public posts, images and video, follow accounts, reply, repost, message each other and ask the built-in Grok AI questions.

How it is run

nine questions
ArchitectureWho holds your account and posts?

One company

open protocol: no

move your account and keep your followers: no

hub: X Corp. (SpaceX)

A closed, centralised service: X Corp. in the US hosts the platform for the Irish operator, and outside access runs only through X's own API, free in small amounts and licensed beyond that. No route was found to move an account with its followers to another provider.

Business modelWho pays, and for what?

Targeted ads · subscriptions · licensing data

In SpaceX's filings, advertising on X brought in $1,844m in 2025, more than the $1,357m of the whole 'AI solutions and infrastructure' line, which bundles X Premium and Grok subscriptions, data licensing (paid access to X data through the developer API) and Grok API sales; so ads come first. That line is not split, so placing subscriptions before data licensing is inference from their larger reported growth. Ads are personalised using X activity and data from ad partners.

OrganisationWhat kind of organisation runs it?

Listed company

control: Space Exploration Technologies Corp. (SpaceX, Nasdaq since June 2026); Elon Musk holds about 82% of the votes

The chain runs X Internet Unlimited Company, X Corp., xAI (which bought X in March 2025) and SpaceX (which bought xAI in February 2026). It was private and investor-backed until SpaceX listed in June 2026; SpaceX is a Nasdaq 'controlled company', and Musk controls the election of all directors and other shareholder votes.

FeedWho decides what you see?

Ranked, with a non-profiled option

For You is ranked by X. Following shows only accounts a user follows, but since November 2025 it is ranked by Grok by default, with a sort to Recent for chronological order; press reported in February 2026 that the sort was missing in the mobile apps for non-Premium accounts while it stayed on the web. X's help pages do not describe a DSA non-profiling option as such.

ModerationWho moderates?

The operator

X's own staff, contractors and automated systems enforce the X Rules; for January to June 2026 its DSA report lists 250 internal and 947 contracted moderators. Community Notes lets volunteer contributors attach context notes to posts; the guide describes adding notes, not removing posts.

AI trainingDoes your content train AI?

Trains its own AI, with an opt-out

a setting or form to opt out: yes

X may share users' public posts, profiles and Grok interactions with xAI, its parent, to train Grok and other xAI models; the 'Grok & Third-party Collaborators' setting opts out, as does protecting one's posts. The privacy policy also reserves sharing with third-party collaborators who may train their own AI unless the user opts out, but the developer agreement bars API customers from training foundation or frontier models and no outside training deal was found, so the answer is own rather than licensed. In August 2024 X agreed with the Irish DPC to suspend using EU users' public posts processed from 7 May to 1 August 2024 for Grok; the DPC opened an inquiry into Grok training in April 2025.

IdentityMust you prove who you are?

No ID needed

verification: Persona

Read off the verification layer, where its sources are.

Open sourceIs the code open?

Partly open

licence: proprietary; the For You ranking code is published under Apache-2.0

Read off the code layer, where its sources are.

SizeHow big is it?

64.7M a month in the EU

counted: average monthly active recipients in the EU, as the DSA requires them

period: Jan–Jun 2026

X's DSA figure for its EU average monthly active recipients, published 31 August 2026; the report does not say how logged-out use is counted.

What each layer rests on

checked 25 Sep 2026
07OperatorWho serves the app?

X Internet Unlimited Company · Ireland

Dublin, CRO 503351, renamed from Twitter International Unlimited Company in 2025. It signs the EU terms, is the GDPR controller and the DSA provider. Designated a very large online platform on 25 April 2023; 64.7 million average monthly active recipients in the EU, January to June 2026.

07OwnerWho owns the operator, where someone else does?

Space Exploration Technologies Corp. (SpaceX) · United States

The chain runs from X Internet Unlimited Company through X Corp. (Nevada) and X.AI Holdings Corp., which bought X in March 2025, to SpaceX, which bought xAI in February 2026 and listed in June 2026. Elon Musk holds about 82% of the votes.

07ProtocolWho writes the rules of the network?

X Corp. · United States

protocol: proprietary

A centralised service. Outside access runs only through X's own API, free in small quantities and licensed beyond that.

07Shared servicesWhat does it lean on but not run?

None

07CodeWho builds the software?

X Corp. and xAI · United States

licence: proprietary; the For You ranking code is published under Apache-2.0

repository

The ranking code has been public since January 2026 in xAI's GitHub organisation. No product engineering for X was found in the EU; xAI's Dublin roles are network and security jobs.

07VerificationWho checks users' identity, age or account?

Persona · United States

checks: identity

ID needed to post: no

The blue check means a paid Premium subscription and an eligibility review, not a verified identity. ID verification with a government ID and a selfie is optional, through Persona, and mandatory only for creator payouts and some safety cases. EU age assurance uses account signals, estimates and ID checks from an unnamed vendor.

06ModelsWhose models moderate, rank or check?

xAI · United States

Grok is built into X, and the For You feed is ranked by a Grok-based transformer. X may share EU users' public posts with xAI to train models, on the basis of legitimate interests, with an opt-out in settings. The Irish DPC's inquiry into that training, opened April 2025, is still open.

05DataWhere does the data sit?

X Internet Unlimited Company · United States

also X Internet Unlimited Company · Ireland: named as a storage location beside the United States, with no EU data centre identified

where: The United States, Ireland and other countries where X operates. X names no EU data centre and makes no promise to keep EU users' data in the EU. Its US parent hosts for the Irish controller.

transfers: To X Corp. in the US, to affiliates including xAI, and to US service providers such as AWS, Google, Microsoft and Oracle, under standard contractual clauses and the EU-US Data Privacy Framework, which X Corp. joined in April 2024.

04ServersWho runs the servers?

X Corp. · United States

region: leased data centres in Hillsboro, Oregon, and Atlanta, per press; no EU data centre named

X's own infrastructure, with AWS, Google, Microsoft and Oracle among its listed service partners. The origin sits behind the CDNs and does not show in a measurement.

04EdgeWho stands in front of them?

Cloudflare · United States

also Fastly · United States: images and video

The European points of presence in the response headers are caches; no EU-hosted origin was found.

  • measured · x.com · AS13335 Cloudflare · 25 Sep 2026
  • measured · api.x.com · AS13335 Cloudflare · 25 Sep 2026
  • measured · pbs.twimg.com · AS54113 Fastly · 25 Sep 2026 · images
  • measured · video.twimg.com · AS54113 Fastly · 25 Sep 2026

where a claim in circulation is wrong

Checked 25 Sep 2026.