PNG Metadata Remover: Strip AI Prompts & Chunks
Strip tEXt, zTXt, and iTXt metadata chunks from PNG files. Remove Stable Diffusion prompts, seeds, ComfyUI node graphs, and C2PA credentials online in your browser.
Understanding PNG Chunk Anatomy & AI Provenance Leaks
The Portable Network Graphics (PNG) format is composed of sequential 4-part data chunks: a 4-byte length, a 4-byte chunk type identifier, variable payload bytes, and a 4-byte CRC-32 checksum. Generative AI tools embed creator data inside ancillary text chunks.
tEXt & zTXt: Prompts, Seeds & Samplers
Automatic1111 and InvokeAI embed your entire positive prompt, negative prompt, seed number, CFG scale, sampler, and model hash inside a tEXt parameters chunk or deflated zTXt chunk.
ComfyUI Workflow Graphs
ComfyUI embeds your entire visual node canvas, custom LoRA configurations, and generation pipelines as a serialized JSON string in a tEXt workflow chunk, exposing proprietary techniques.
iTXt: International Text & C2PA Credentials
Adobe Firefly, DALL-E, and modern generative platforms embed cryptographically signed C2PA provenance manifests and UTF-8 XMP metadata inside international iTXt chunks.
PNG Chunk Architecture & Engine Slicing Rules
The PNG specification categorizes chunks into Critical (required for rendering) and Ancillary (metadata and optional profiles).
| Chunk Identifier | Chunk Category | Typical Embedded Content | Engine Action in Mode A |
|---|---|---|---|
| IHDR / IEND | Critical | Image header (dimensions, bit depth) & stream end marker | Strictly validated & preserved |
| IDAT / PLTE | Critical | Compressed pixel raster stream & indexed palette | Bit-for-bit identical copy |
| tEXt / zTXt | Ancillary | AI prompts, negative prompts, seeds, ComfyUI workflow JSON | Excised from stream |
| iTXt | Ancillary | International UTF-8 text, XMP packets, C2PA manifests | Excised from stream |
| eXIf / tIME | Ancillary | EXIF camera metadata & modification timestamps | Excised from stream |
| iCCP / sRGB / gAMA | Ancillary | ICC Color profiles, standard color space & gamma | Whitelisted & preserved |
How to Strip Prompts and Metadata from PNG Images
Clean your PNG artwork in four immediate steps with complete alpha preservation.
Select PNG File
Drag and drop your .png image into the in-browser dropzone.
Inspect AI Prompts & Chunks
Review extracted Stable Diffusion prompts, seeds, model names, and ComfyUI workflow JSON in the inspection report.
Select Cleaning Mode
Choose Mode A for lossless chunk stripping or Mode B for complete canvas raster re-encoding.
Download Clean PNG
Click Sanitize & Remove Metadata to export a sanitized PNG with all prompt and provenance chunks permanently stripped.
Frequently Asked Questions About PNG Metadata Removal
Does this tool strip Stable Diffusion prompts and seeds from PNG files?
Yes. Stable Diffusion tools (Automatic1111, Forge, InvokeAI) store prompts, negative prompts, seeds, samplers, and model checkpoints inside uncompressed tEXt or compressed zTXt parameters chunks. Mode A excises these chunks completely.
Can it remove ComfyUI workflow node graphs embedded in PNGs?
Yes. ComfyUI embeds your entire node workflow graph as a JSON string inside a tEXt workflow or prompt chunk. Our parser identifies and removes these chunks, protecting your proprietary workflow graphs.
Is alpha transparency preserved when removing metadata from PNGs?
Yes. In Mode A, pixel IDAT chunks and the 32-bit RGBA alpha channel are untouched bit-for-bit. In Mode B, canvas re-encoding specifically preserves alpha transparency during re-export.
Are color management profiles like Display P3 preserved?
Yes. Our binary chunk surgeon specifically whitelists color management chunks (iCCP, sRGB, gAMA, cHRM) while discarding only text and provenance chunks, guaranteeing accurate color rendering.