Claude

At a glance

Images

Content CredentialsA signed record (C2PA) of how the file was made, sealed so any change shows.

Anthropic's October 8, 2026 help article says that when Claude generates a supported file type such as a PNG or JPEG, it will attach a signed Content Credential (C2PA). Its API documentation says image files that Claude produces in the code execution sandbox carry one when downloaded through the Files API, and lists PNG, JPEG, GIF, WebP, TIFF, HEIC, AVIF and SVG.

These pages cover image files Claude creates; they do not describe an image-generation model. Anthropic's model table, dated October 8, 2026, lists Content Credentials in files for all 16 models it covers.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Anthropic's commitments under the Code (first bullet)

New models will mark AI-generated content from day one. Claude models launched in the EU on or after August 2, 2026 will support machine-readable marking at launch. Generated text will carry embedded watermarks, and generated files will include Content Credentials (C2PA) where supported.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Which Claude models support watermarking (table and footnote)

*Rollout on Amazon Bedrock will complete by October 17. […] Consistent with our commitments under the Code, Anthropic is adding watermarks to outputs from models released before August 2, 2026." Model table (reproduced cell by cell from the page HTML, ledger/snapshots/S-2016.html; "Yes" as shown, "(blank)" = empty cell): | Model | Text watermarks in Claude output (first-party surfaces) | Text watermarks in cloud partner output (AWS, Google Cloud, Microsoft Foundry) | Content Credentials (C2PA) in files | |—|—|—|—| | Claude Fable 5.1 | Yes | Yes | Yes | | Claude Fable 5 | Yes | Yes* | Yes | | Claude Mythos 5.1 | Yes | Yes | Yes | | Claude Mythos 5 | (blank) | (blank) | Yes | | Claude Opus 5.5 | Yes | Yes | Yes | | Claude Opus 5 | Yes | Yes | Yes | | Claude Opus 4.8 | Yes | Yes* | Yes | | Claude Opus 4.7 | (blank) | (blank) | Yes | | Claude Opus 4.6 | (blank) | (blank) | Yes | | Claude Opus 4.5 | (blank) | (blank) | Yes | | Claude Sonnet 5.5 | Yes | Yes | Yes | | Claude Sonnet 5 | Yes | Yes* | Yes | | Claude Sonnet 4.6 | (blank) | (blank) | Yes | | Claude Sonnet 4.5 | (blank) | (blank) | Yes | | Claude Haiku 5.5 | Yes | Yes | Yes | | Claude Haiku 4.5 | (blank) | (blank) | Yes |

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage How Claude marks content: 2. Content Credentials (C2PA)

When Claude generates a supported file type such as a PNG or JPEG, it will attach signed provenance metadata. This metadata is called a Content Credential and follows the Coalition for Content Provenance and Authenticity (C2PA) open standard, which is used across the industry to record information about content provenance. If a signed metadata label is present, it signals that a file was processed by Claude.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

On the Claude API, supported image, video, and audio files that Claude produces in the code execution sandbox carry C2PA Content Credentials when you download them through the Files API . Supported formats include PNG, JPEG, GIF, WebP, TIFF, HEIC, AVIF, SVG, MP4, MOV, MP3, WAV, FLAC, and M4A.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Invisible watermarkA signal woven into the pixels, frames, audio or wording, meant to survive copying.

Not stated. None of Anthropic's pages listed under Sources read says so.

Anthropic's pages describe a watermark in text and Content Credentials in files; they describe no watermark in image pixels.

AI label in metadataA plain metadata field (IPTC Digital Source Type) saying AI made the content. Anyone can add or remove it.

Not stated. None of Anthropic's pages listed under Sources read says so.

Visible markA mark you can see, such as a logo or a sparkle in a corner.

Not stated. None of Anthropic's pages listed under Sources read says so.

Tool named in metadataThe tool or model written into ordinary file fields, such as Software or Creator.

Anthropic's API documentation says the Content Credential names Anthropic as the issuer, carries a timestamp and records the action "Claude provided this file at the request of a user and may have created or modified the file contents." It says the credential records nothing about the user, organization or request.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 2)

Signing requires no changes to your requests or response handling, and the manifest records nothing about you, your organization, or your request. The file's visible content is unchanged. […] Text files, PDFs, and office documents are not signed because they are not supported formats for signing.

Video

Content CredentialsA signed record (C2PA) of how the file was made, sealed so any change shows.

Anthropic's API documentation says MP4 and MOV files that Claude produces in the code execution sandbox carry a Content Credential (C2PA) naming Anthropic as the issuer when downloaded through the Files API.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

On the Claude API, supported image, video, and audio files that Claude produces in the code execution sandbox carry C2PA Content Credentials when you download them through the Files API . Supported formats include PNG, JPEG, GIF, WebP, TIFF, HEIC, AVIF, SVG, MP4, MOV, MP3, WAV, FLAC, and M4A.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Invisible watermarkA signal woven into the pixels, frames, audio or wording, meant to survive copying.

Not stated. None of Anthropic's pages listed under Sources read says so.

AI label in metadataA plain metadata field (IPTC Digital Source Type) saying AI made the content. Anyone can add or remove it.

Not stated. None of Anthropic's pages listed under Sources read says so.

Visible markA mark you can see, such as a logo or a sparkle in a corner.

Not stated. None of Anthropic's pages listed under Sources read says so.

Tool named in metadataThe tool or model written into ordinary file fields, such as Software or Creator.

The same Content Credential fields as for images: Anthropic as the issuer, a timestamp, and the action description that Claude provided the file at the request of a user and may have created or modified it.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Audio

Content CredentialsA signed record (C2PA) of how the file was made, sealed so any change shows.

Anthropic's API documentation says MP3, WAV, FLAC and M4A files that Claude produces in the code execution sandbox carry a Content Credential (C2PA) naming Anthropic as the issuer when downloaded through the Files API.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

On the Claude API, supported image, video, and audio files that Claude produces in the code execution sandbox carry C2PA Content Credentials when you download them through the Files API . Supported formats include PNG, JPEG, GIF, WebP, TIFF, HEIC, AVIF, SVG, MP4, MOV, MP3, WAV, FLAC, and M4A.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Invisible watermarkA signal woven into the pixels, frames, audio or wording, meant to survive copying.

Not stated. None of Anthropic's pages listed under Sources read says so.

AI label in metadataA plain metadata field (IPTC Digital Source Type) saying AI made the content. Anyone can add or remove it.

Not stated. None of Anthropic's pages listed under Sources read says so.

Visible markA mark you can see, such as a logo or a sparkle in a corner.

Not stated. None of Anthropic's pages listed under Sources read says so.

Tool named in metadataThe tool or model written into ordinary file fields, such as Software or Creator.

The same Content Credential fields as for images: Anthropic as the issuer, a timestamp, and the action description that Claude provided the file at the request of a user and may have created or modified it.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 1)

The credential is a cryptographically signed manifest embedded in the file's metadata. It identifies Anthropic as the issuer, carries a timestamp, and records the action description "Claude provided this file at the request of a user and may have created or modified the file contents."

Text

Content CredentialsA signed record (C2PA) of how the file was made, sealed so any change shows.

Not stated. None of Anthropic's pages listed under Sources read says so.

Invisible watermarkA signal woven into the pixels, frames, audio or wording, meant to survive copying.

Anthropic's October 8, 2026 help article says supported Claude models weave an imperceptible watermark into generated text at the model level, and that marks will apply across Claude Platform (API), Claude, Claude Code, Claude Cowork and Claude Tag worldwide, though some platforms or features may not support certain marking types. It says supported models used through AWS, Google Cloud or Microsoft Foundry will carry watermarks; its model table of the same date shows the watermark on nine models and not on seven older ones, and Anthropic says it is adding watermarks to models released before August 2, 2026.

Anthropic says the watermark travels with copied text and may persist through some editing. It does not name the watermark. Anthropic made these marking commitments as a signatory of the EU AI Act's Article 50(2) Code of Practice on transparency of AI-generated content.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Introduction (para 1)

Anthropic has signed the EU AI Act's Article 50(2) Code of Practice on Transparency of AI-Generated Content, as a provider of both generative AI models and generative AI systems.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Anthropic's commitments under the Code (first bullet)

New models will mark AI-generated content from day one. Claude models launched in the EU on or after August 2, 2026 will support machine-readable marking at launch. Generated text will carry embedded watermarks, and generated files will include Content Credentials (C2PA) where supported.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Anthropic's commitments (second bullet); What's covered: Regions

Marking works everywhere you use Claude. Marks will apply to output from supported Claude models across Claude Platform (API), Claude, Claude Code, Claude Cowork, and Claude Tag, and wherever Claude is offered, worldwide. Some platforms or features may not support certain marking types. […] Regions. Marking will apply to output from supported models wherever Claude is offered, worldwide.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage What's covered: Products; Cloud partners

Products. Claude markings cover output from supported models everywhere you use Claude, including Claude Platform (API), Claude, Claude Code, Claude Cowork, and Claude Tag. Embedded watermarks will apply to all generated text. Content Credentials (C2PA) will apply where Claude supports processing files. Cloud partners. When supported Claude models are accessed through AWS, Google Cloud, or Microsoft Foundry they will carry watermarks. Content Credentials (C2PA) are added when Claude creates a file, so it applies only where a platform offers Claude's file generation features

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Which Claude models support watermarking (table and footnote)

*Rollout on Amazon Bedrock will complete by October 17. […] Consistent with our commitments under the Code, Anthropic is adding watermarks to outputs from models released before August 2, 2026." Model table (reproduced cell by cell from the page HTML, ledger/snapshots/S-2016.html; "Yes" as shown, "(blank)" = empty cell): | Model | Text watermarks in Claude output (first-party surfaces) | Text watermarks in cloud partner output (AWS, Google Cloud, Microsoft Foundry) | Content Credentials (C2PA) in files | |—|—|—|—| | Claude Fable 5.1 | Yes | Yes | Yes | | Claude Fable 5 | Yes | Yes* | Yes | | Claude Mythos 5.1 | Yes | Yes | Yes | | Claude Mythos 5 | (blank) | (blank) | Yes | | Claude Opus 5.5 | Yes | Yes | Yes | | Claude Opus 5 | Yes | Yes | Yes | | Claude Opus 4.8 | Yes | Yes* | Yes | | Claude Opus 4.7 | (blank) | (blank) | Yes | | Claude Opus 4.6 | (blank) | (blank) | Yes | | Claude Opus 4.5 | (blank) | (blank) | Yes | | Claude Sonnet 5.5 | Yes | Yes | Yes | | Claude Sonnet 5 | Yes | Yes* | Yes | | Claude Sonnet 4.6 | (blank) | (blank) | Yes | | Claude Sonnet 4.5 | (blank) | (blank) | Yes | | Claude Haiku 5.5 | Yes | Yes | Yes | | Claude Haiku 4.5 | (blank) | (blank) | Yes |

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage How Claude marks content: 1. Embedded watermarks in text

When a supported Claude model generates text, it weaves an imperceptible watermark directly into the text itself. You won’t see it, and it doesn’t change the meaning, quality, or readability of Claude’s response. Because the watermark is part of the text, it will travel with the text when it’s copied and pasted elsewhere, and may persist through some editing. Watermarking will be applied at the model level, which means it will be present no matter which Claude product or surface the text comes from.

AI label in metadataA plain metadata field (IPTC Digital Source Type) saying AI made the content. Anyone can add or remove it.

Not stated. None of Anthropic's pages listed under Sources read says so.

Visible markA mark you can see, such as a logo or a sparkle in a corner.

Not stated. None of Anthropic's pages listed under Sources read says so.

Tool named in metadataThe tool or model written into ordinary file fields, such as Software or Creator.

Not stated. None of Anthropic's pages listed under Sources read says so.

Documents and code

Content CredentialsA signed record (C2PA) of how the file was made, sealed so any change shows.

Anthropic's API documentation says text files, PDFs and office documents that Claude produces are not signed with a Content Credential.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 2)

Signing requires no changes to your requests or response handling, and the manifest records nothing about you, your organization, or your request. The file's visible content is unchanged. […] Text files, PDFs, and office documents are not signed because they are not supported formats for signing.

Invisible watermarkA signal woven into the pixels, frames, audio or wording, meant to survive copying.

Not stated. None of Anthropic's pages listed under Sources read says so.

Anthropic says the text watermark will apply to all generated text, but does not say whether text inside files Claude creates, such as documents, spreadsheets, slides and code files, carries it.

AI label in metadataA plain metadata field (IPTC Digital Source Type) saying AI made the content. Anyone can add or remove it.

Not stated. None of Anthropic's pages listed under Sources read says so.

Visible markA mark you can see, such as a logo or a sparkle in a corner.

Not stated. None of Anthropic's pages listed under Sources read says so.

Tool named in metadataThe tool or model written into ordinary file fields, such as Software or Creator.

Not stated. None of Anthropic's pages listed under Sources read says so.

Limits and detection

Checking tool from the makerA way the maker offers to check a file for its traces.

Anthropic's free Claude Content Checker runs in the browser and checks image, video and audio files up to 100 MB for a Claude Content Credential; it does not check text. Text watermark detection is in private preview for eligible organizations such as regulators, law enforcement, media, fact-checkers and researchers.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Detect Claude's marks

Detection checks whether a piece of text or a file carries a supported Claude mark. If a supported mark is found, it indicates that the content may have been generated or processed by Claude. […] To check whether a file contains a Claude-issued Content Credential, use the free Claude Content Checker […] Watermark detection is currently in private preview, available to eligible organizations as required under EU law (such as regulators, law enforcement, media, fact-checkers, independent researchers, educational organizations, and EU civil society groups). It is also available for enterprises who are similarly obligated to verify watermarking for their own compliance with the Act.

Check if files were made with ClaudeAnthropic

Quoted passage Check a file; What the tool does; How it works

Supported formats: JPG, PNG, GIF, WEBP, TIFF, HEIC, AVIF, SVG, DNG, JXL, MP4, MOV, AVI, WAV, MP3, M4A, FLAC · up to 100 MB […] This tool runs in your browser. Your file never leaves your device. […] The tool checks a file for a Content Credential from Claude. If it finds one, that tells you Claude may have made or processed the file. It doesn't tell you who authored the underlying content, and it carries no identifying information about the user. The tool does not check text. Claude marks text with a watermark in the writing itself. […] When Claude produces a supported file type (such as a .png, .jpg, or .svg), it attaches a Content Credential in the form of a small, cryptographically signed note in the file’s metadata, saying that the file may have been made or processed with Claude.

What the maker says about limitsIn the maker's own words.

Anthropic says Claude content may carry no detectable mark if it was made before marking was supported, heavily edited, paraphrased or translated, very short, stripped of metadata by conversion, re-saving or screenshots, or produced where a marking type is not supported.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Limitations (absence of a mark)

Lack of a detected mark doesn’t mean the content wasn’t AI-generated or processed. Content generated by Claude may not carry a detectable mark if, for example: It was generated by a model before marking was supported for that model; The text has been heavily edited, paraphrased, translated, or mixed into other writing; The passage is very short, leaving too little text for a reliable signal; A file’s metadata was stripped through format conversion, re-saving, screenshots, or other means; It was produced through a platform, feature, or file type where a particular marking type wasn’t supported.

What the maker says about limitsIn the maker's own words.

Anthropic says a detected mark shows that Claude processed the content but is not fully conclusive, because Claude may not be the original author.

How Claude marks AI-generated contentAnthropic (Claude Help Center)

Quoted passage Limitations (detected mark)

A detected mark provides a signal that content was processed by Claude, but is not fully conclusive. Detecting a Claude mark tells you that the content may have been processed by Claude. It does not, on its own, confirm the full provenance of the content. For example: Claude may not be the original author. People often use Claude to proofread, translate, summarize, or convert files. The output can carry a Claude mark even if the underlying ideas, text, or data originated from another source;

What the maker says about limitsIn the maker's own words.

Anthropic says re-encoding, format conversion, screenshots and metadata-stripping tools remove the Content Credential, so a missing credential does not mean a file was not produced with Claude.

Code execution tool (Claude Platform Docs)Anthropic (Claude Platform Docs)

Quoted passage Content Credentials on generated files (para 3)

To verify a credential, inspect the file with any C2PA-compatible tool, such as the open-source c2patool command-line utility . Re-encoding, format conversion, screenshots, and tools that strip metadata remove the credential, so a missing credential doesn't mean a file wasn't produced with Claude.