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Delete Image Metadata

Remove Metadata From PNG Files

PNG stores metadata in chunks, not EXIF segments. That includes the text chunks where AI image tools write their prompts and seeds.

  • .png
Free
No account, no limit on files
0
Files uploaded — processing is local
PNG
Lossless — pixels never re-encoded
Processed in your browser
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How PNG chunks work

A PNG file is an eight-byte signature followed by a list of chunks. Each chunk has a four-byte length, a four-byte type code, its data, and a CRC-32 checksum of the type and data. Because every chunk carries its own checksum and its own length, chunks can be removed individually without invalidating anything else in the file.

The case of the letters in a type code is meaningful. A lowercase first letter means the chunk is ancillary — a decoder that does not understand it may ignore it. That is why text and timestamp chunks can be dropped safely while IHDR, PLTE, IDAT and IEND, the critical chunks, must be preserved exactly.

  • IHDR — the header: dimensions, bit depth, colour type. Critical, always kept.
  • IDAT — the compressed pixel data, often split across many chunks. Critical, copied through untouched.
  • tEXt — Latin-1 keyword and value pairs: Author, Software, Comment, Copyright, Description.
  • zTXt — the same, but compressed. Common in files carrying long text.
  • iTXt — UTF-8 text with a language tag. This is where XMP is stored in a PNG.
  • eXIf — added in PNG 1.5, carrying the same tag structure a JPEG's EXIF block would, including GPS.
  • tIME — the last-modification timestamp, to the second.
  • iCCP — the embedded ICC colour profile. Kept by default so colours do not shift.

PNG is where AI generation data lives

Stable Diffusion interfaces default to PNG, and they use text chunks to record how an image was made. Automatic1111 and Forge write a chunk with the keyword 'parameters' containing the prompt, negative prompt, steps, sampler, CFG scale, seed, dimensions and model hash as one plain-text string. ComfyUI writes the entire node graph as JSON, which can run to tens of kilobytes.

None of this is hidden or encrypted — it is plain text inside the file, visible to anyone who opens it in a metadata viewer or even a text editor. The analysis table on this page shows those chunks with their keywords so you can see exactly what would have been published with the image.

Screenshots, exports and what PNGs usually carry

PNGs from a screenshot tool or a design app carry less than a camera photo, but rarely nothing. Typical contents are a Software tag naming the application, a creation or modification timestamp, an sRGB or iCCP colour profile, and on macOS an iTXt chunk containing XMP with the device and OS version.

Removing them is genuinely lossless in PNG's case in a stronger sense than in JPEG's: PNG compression is itself lossless, and the IDAT chunks are copied without being decompressed, so the pixel data in the cleaned file is bit-identical.

What this tool does

  • Removes tEXt, zTXt, iTXt, eXIf and tIME chunks in one pass
  • Surfaces AI generation parameters and ComfyUI workflows before removal
  • Pixel data is bit-identical: IDAT chunks are never decompressed or re-encoded

What it does not do

  • The iCCP colour profile is kept by default; there is a toggle to remove it
  • Compressed zTXt chunks are removed but not decompressed for display
  • Animated PNG (APNG) frame chunks are preserved, since they are image data

Remove Metadata From PNG Files

PNG stores metadata in chunks, not EXIF segments. That includes the text chunks where AI image tools write their prompts and seeds.

Open the tool

Reviewed and updated . Behaviour described on this page is covered by the project’s automated tests.

Frequently asked questions

Do PNG files contain EXIF data?

They can. PNG 1.5 introduced the eXIf chunk, which holds the same tags a JPEG would, including GPS. Many phone screenshots and format conversions carry one.

How do I remove the Stable Diffusion prompt from a PNG?

Load the file here — the prompt appears as a text chunk, usually named 'parameters' — then remove the metadata. The chunk is deleted and the image data is untouched.

Does removing PNG metadata change the image at all?

No. The compressed pixel chunks are copied verbatim, so the cleaned PNG decodes to exactly the same pixels.

Why is my PNG's metadata so large?

Usually a ComfyUI workflow or an XMP block. Node graphs stored as JSON can be tens of kilobytes, sometimes larger than a small image itself.

Will removing the tIME chunk hide when I made the file?

It removes the timestamp stored inside the image. Your filesystem still records its own dates, and those travel with the file in some upload and archive formats.

Does removing chunks break the PNG checksum?

No. Each chunk carries its own CRC, so dropping one leaves every remaining chunk valid.

Are APNG animations supported?

Yes. Animation frames are image data and are preserved; only text and timestamp chunks are removed.

Why does my PNG have an eXIf chunk?

PNG 1.5 added it, and phone screenshots and format conversions frequently carry one — including GPS coordinates inherited from an original photo.

Does the tool decompress zTXt chunks?

No. Compressed text chunks are removed without being decompressed for display, so their contents are shown as compressed rather than in full.

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