What Experiments and Tools Are Available on 29a.ch?

29a.ch is the personal website of Jonas Wagner, and its main draw is a collection of browser-based experiments and tools. The site's own listing highlights four in particular: TimeStretch Player (independent audio speed and pitch control), Analog Film Emulator (analog film look), Forensically (photo forensics), and Neonflames (drawing nebulae in the browser). All of these are presented as experiments you can open and use directly, with no account or installation described on the site.

The four highlighted experiments

TimeStretch Player

An audio player that can change the speed and pitch of audio independently. That means you can slow a track down without dropping its pitch, or shift the pitch without changing how fast it plays — useful for practice, transcription, or just experimenting with how a recording sounds.

Analog Film Emulator

A tool to emulate the look of analog film. If you want a photo to carry the color and grain character associated with film rather than a clean digital rendering, this is the experiment aimed at that effect.

Forensically

A set of tools to forensically analyze photos. This is the most actively documented of the group: the site's recent articles describe adding C2PA (Content Provenance and Authenticity) metadata reading to it.

A few practical points from that write-up are worth knowing before you rely on it:

• What C2PA support does: it reads signed provenance metadata attached to media, which is meant to certify the source and history of a file.
• What it does not do: a digital signature does not by itself guarantee trustworthiness. As the author puts it, you still need to trust everyone and everything with access to the keys. The C2PA JavaScript library reportedly exposes little beyond basic signature info (algorithm, issuer, certificate serial number, timestamp), and the public verification site is similarly limited — there is a "known certificate list" and an email address for submitting a certificate, but it isn't clear what is validated before inclusion. The author's own advice is to take the signatures displayed in Forensically "with a big pinch of salt."
• Remote manifests are disabled: C2PA supports remote manifests, which can be useful for keeping file sizes small, but they can also act as beacons that track who views the metadata. Forensically blocks them both through configuration and a Content Security Policy.
• Size trade-off: the c2pa-js library compiles to roughly 350 kB for the main ES module, 165 kB for a worker, and 5.4 MB for the WebAssembly module in the author's Vite setup.

Neonflames

Draw your own nebula right in your browser. This is the purely creative entry in the list — an interactive canvas for generating nebula imagery rather than an analysis or audio tool.

How to choose between them

Beyond the four

The site also links to a full "View all my experiments" page, so the four above are a starting set rather than the complete catalog. It additionally publishes recent articles — for example, "C2PA Content Credential Photo Forensics" (2025-04-12) — which document how the tools are built and what their limits are. If you're evaluating Forensically for anything consequential, reading that article first will tell you more about what its C2PA output can and cannot support than the tool interface alone.