The extension analyzes images in the TYPO3 file manager using an AI-powered Vision API and generates descriptive alternative texts from them. These suggestions appear directly in the Filelist module of the TYPO3 backend and can be accepted or adjusted by editors. The extension is explicitly designed for accessibility, not for SEO purposes.

The extension supports TYPO3 version 12 and above, including TYPO3 v14, and requires PHP 8.2. It is available in the official TYPO3 Extension Repository (TER) and can be installed via Packagist using composer require mfd/ai-filemetadata.

The extension itself is open source and free of charge. However, generating alt texts requires an API key from an OpenAI-compatible service, which incurs costs. In practice, these costs are minimal: in our own tests, we paid less than one euro for 100 images.

We use ai_filemetadata on marketing-factory.com itself and have integrated it into the SEGGER project. With nearly 20,000 downloads in the TYPO3 Extension Repository, it is also being adopted by a growing number of other TYPO3 projects worldwide.

The European Accessibility Act (EU Directive 2019/882), implemented in Germany as the Barrierefreiheitsstärkungsgesetz (BFSG), requires operators of many websites and online shops to make their digital services accessible. Missing or inadequate alt texts are considered a barrier for visually impaired users and can lead to legal consequences.

No. SEO alt texts typically contain keywords but do not describe the actual image content. Accessibility requires a precise description of what is shown in the image, so that screen reader users can fully understand the visual context. ai_filemetadata is explicitly designed to generate this type of descriptive alt text.

The WCAG guidelines distinguish between informative images, which require a descriptive alt text, decorative images, which should have an empty alt attribute, and functional images such as icons or buttons, where the function rather than the appearance is described. ai_filemetadata is designed for informative images. Automatic detection of decorative images is planned as a future feature.

For a detailed overview, see our blog post: BFSG: What is the right alt text for which images?

By default, the extension uses the OpenAI Vision API with the gpt-4o-mini model. However, it can be configured to work with any OpenAI-compatible API endpoint, such as Mittwald's AI hosting or other self-hosted models.

Yes. ai_filemetadata supports all active languages configured in a TYPO3 instance. Alt texts are generated separately for each language. A folder-based language mapping in system/settings.php allows you to define which languages apply to specific storage folders.

Yes. The prompt sent to the AI model can be customized in the extension configuration under Alt Text Prompt, for example to adjust the tone, language style, or length of the generated texts. Configuration is done under Admin Tools > Settings > Extension Configuration.

Not necessarily. The extension offers optional image resizing before transmission. Since a resolution of 512x512 pixels is sufficient for image analysis in most cases, this significantly reduces the number of tokens processed and therefore the API costs.

Note: Resizing is performed at runtime by TYPO3. With large image collections or high-resolution originals, this can lead to noticeably longer processing times and increased server load. It is advisable to test this option with a limited number of images before rolling it out in production.

Yes. The extension includes a CLI command that generates alt texts for all images within a given folder in a batch process:

bin/typo3 ai:generate-alt-texts --path="1:my-folder/" [--overwrite] [--limit=1]

The optional --overwrite flag replaces existing alt texts, while --limit restricts the number of images processed per run. This is especially useful when rolling out the extension on sites with an existing large image library.

Yes. Specific folder paths can be excluded from processing via system/settings.php. This is useful for directories containing sensitive content or images whose license terms prohibit processing by external AI services.

Images are transmitted to the configured external API service for analysis. Before using the extension, you should verify that this data transfer complies with your privacy policy. The same applies to image licenses: some license models explicitly prohibit the use of content for AI processing.

Yes. The extension generates suggestions, not final texts. All generated alt texts can be edited or overwritten at any time in the TYPO3 backend. Editorial control remains entirely with your team.

ai_filemetadata is an open source project and contributions are very welcome. The full source code is available on GitHub. Bug reports, feature requests, and pull requests can be submitted via the issue tracker. For commercial support or custom development, feel free to contact us directly.

This is the typical starting point: a grown image library, thousands of files, few or no alt texts. A two-step approach works well here.

Step 1: Process the existing library via CLI. The extension's CLI command allows you to generate alt texts for all images in a folder in one batch run:

bin/typo3 ai:generate-alt-texts --path="1:my-folder/"

This can be done incrementally, folder by folder, adapted to the available time and server resources.

Step 2: Establish a sustainable editorial workflow. Ensuring that new images are consistently handled going forward requires more than a tool. We help build an editorial process within TYPO3 that ensures alt texts are systematically reviewed and approved, for example using workflow mechanisms in the TYPO3 backend.