CA AB853: California AI Transparency Act.

In one paragraph

California's AB 853 amended the California AI Transparency Act (SB 942 of 2024), moving its operative date from January 1, 2026 to August 2, 2026. From January 1, 2027, large online platforms (over 2,000,000 monthly users) must detect provenance data, show whether content was generated or substantially altered by GenAI or captured by a device, and, where feasible, not knowingly strip it; GenAI hosting sites may not knowingly offer noncompliant systems. From 2028, new capture devices must embed latent disclosures by default where feasible. $5,000 per violation. Amended by AB 2713 and SB 1000 (Chapters 856, 861 of 2026). Signed October 13, 2025 (Chapter 674); effective January 1, 2026.

Plain-English summary, written with AI assistance. The official text controls.

What it means for business

GenAI providers (no user threshold since SB 1000; assistive tech exempt until 2029) owe the Act's tool and disclosure duties. From 2027, large platforms must show and not strip provenance data and model hosts can't knowingly offer non-compliant GenAI; device makers from 2028. $5,000/violation.

Key provisions

1. 1Moved the operative date of the California AI Transparency Act (Bus. & Prof. Code § 22757 et seq.) from January 1, 2026 to August 2, 2026 (§ 22757.6). AB 853 kept the covered-provider threshold of over 1,000,000 monthly users; SB 1000 (Chapter 861, Statutes of 2026, an urgency law effective September 30, 2026) deleted it, so anyone who produces a GenAI system publicly accessible in California is now a covered provider
2. 2SB 1000 also renamed the AI detection tool a "disclosure verification tool", dropped the option for manifest disclosures, added whether the GenAI system created or altered the content to the required latent disclosure, exempted GenAI systems designed primarily as assistive technology until January 1, 2029, and set a $50,000 per-violation penalty, until that date, for falsely claiming that status
3. 3Large online platform: a public-facing social media, file-sharing or mass messaging platform or stand-alone search engine distributing others' content that exceeded 2,000,000 unique monthly users in the preceding 12 months; broadband and telecommunications services excluded
4. 4From January 1, 2027 (§ 22757.3.1, as amended by AB 2713, Chapter 856, Statutes of 2026), large online platforms must detect provenance data embedded in, attached to or associated with content they distribute and provide a clear and conspicuous interface that reliably indicates whether system provenance data or a digital signature identifies the content as generated or substantially altered by GenAI or captured by a device, naming the GenAI system or device
5. 5Users must be able to inspect system provenance data through the interface, a link (including a third-party site) or a download, subject to federal copyright law; platforms need not maintain, display or allow download of personal information, and may not, to the extent technically feasible, knowingly strip system provenance data or digital signatures from content uploaded, distributed or downloaded. Nothing is required for data not compliant or interoperable with widely adopted standards
6. 6From January 1, 2027 (§ 22757.3.2), a GenAI hosting platform (a website or app that makes GenAI source code or model weights available for download) may not knowingly make available a GenAI system that does not place the disclosures required by § 22757.3
7. 7From January 1, 2028 (§ 22757.3.3), for capture devices (cameras, phones with cameras or microphones, voice recorders) first produced for sale in California on or after that date, manufacturers must offer a latent disclosure of the maker, device name and version, and time and date of creation or alteration, embedded by default, to the extent technically feasible and compliant with widely adopted specifications
8. 8Civil penalty of $5,000 per violation in actions by the Attorney General, a city attorney or county counsel, plus attorney's fees; each day a covered provider, large online platform or capture device manufacturer is in violation is a separate violation. Signed October 13, 2025 (Chapter 674, Statutes of 2025); effective January 1, 2026; Act operative August 2, 2026, platform and hosting duties January 1, 2027, capture-device duties January 1, 2028

Latest legislative action

Oct 13, 2025. Chaptered by Secretary of State - Chapter 674, Statutes of 2025.

Sponsors (showing 5 of 31)

Roll call votes (showing 3 of 9)

Related and companion bills

• California SB1000California AI Transparency Act.
• California SB942California AI Transparency Act.