tEXt: simple keyword and value
The PNG tEXt chunk stores a Latin-1 keyword followed by text. Generators frequently use keys such as parameters, prompt, or workflow.
iTXt: international text
The iTXt chunk supports UTF-8 text, optional language information, and optional compression. This release reads uncompressed iTXt values and explicitly reports compressed entries it cannot yet decode.
zTXt: compressed text
A zTXt chunk signals compressed text. The current browser reader identifies its key and presence but does not claim to have extracted a value unless decompression actually succeeds.
EXIF, XMP, and provenance
PNG may also carry an eXIf chunk, XMP text, or C2PA data in supported structures. The report keeps ordinary metadata and signed provenance separate because they have different validation semantics.
Reading a chunk does not prove the embedded text is truthful. It proves that the inspected file stores that byte sequence under the reported container.