Remove metadata from a PNG

What can be inside a PNG

A PNG is a list of chunks. The ones that carry information about the file rather than the picture are:

• tEXt, zTXt, iTXt: key/value text. AI tools and editors write things like Software, Comment, parameters, or prompt here. XMP is stored in an iTXt chunk with the key XML:com.adobe.xmp.
• eXIf: a full EXIF block, which can hold camera model and GPS.
• tIME: the last modification time.
• caBX: a C2PA manifest, the signed record behind Content Credentials.

The chunks you want to keep are different: the pixel data, transparency, gamma, the embedded colour profile, and the physical size. A good remover takes the first group and leaves the second alone.

Test 1: a PNG with everything, All metadata

This PNG has an eXIf block with camera and GPS, an XMP packet with an AI source type and a creator, text chunks named Software, Comment, Author, Make, and Model.

Before (what the tool listed)	After (re-scan of the download)
AI-related text (Comment): Comment AI-related text (Software): Software AI / provenance XMP: DigitalSourceType GPS in eXIf: 31.23040, 121.47370 EXIF (eXIf): Apple iPhone 15 Pro Camera: Apple iPhone 15 Pro XMP text chunk: XML:com.adobe.xmp Text chunk (Author): tEXt Text chunk (Make): tEXt Text chunk (Model): tEXt	Nothing found. Banner: “Cleaned. 10 fields removed — your picture is unchanged.”

• Download: PNG, 1200x800, 1.95 MB.
• Second opinion (ExifTool 13.25): 24 metadata tags before, 0 after.
• Pixels: decoded RGB values identical to the original (compared in Python).
• Time in the tool: 196 ms in headless Chrome on a server CPU. A phone will be slower.

Ten fields found, ten removed, and a second tool (ExifTool) agrees: 24 metadata tags before, none after.

Test 2: the same file in AI only mode

The same PNG again with the narrower mode. It is the useful comparison because it is the mode people pick first.

Before (what the tool listed)	After (re-scan of the download)
AI-related text (Comment): Comment AI-related text (Software): Software AI / provenance XMP: DigitalSourceType GPS in eXIf: 31.23040, 121.47370 EXIF (eXIf): Apple iPhone 15 Pro Camera: Apple iPhone 15 Pro XMP text chunk: XML:com.adobe.xmp Text chunk (Author): tEXt Text chunk (Make): tEXt Text chunk (Model): tEXt	GPS in eXIf: 31.23040, 121.47370 EXIF (eXIf): Apple iPhone 15 Pro Camera: Apple iPhone 15 Pro Text chunk (Author): tEXt Text chunk (Make): tEXt Text chunk (Model): tEXt

• Download: PNG, 1200x800, 1.96 MB.
• Second opinion (ExifTool 13.25): 24 metadata tags before, 18 after (PNG Author, PNG Make, PNG Model, IFD0:Make, IFD0:Model, IFD0:YCbCrPositioning, ExifIFD:ExifVersion, ExifIFD:DateTimeOriginal).
• Pixels: decoded RGB values identical to the original (compared in Python).
• Time in the tool: 219 ms in headless Chrome on a server CPU. A phone will be slower.

AI only removed the AI-flavoured fields (the Software and Comment text, the XMP with the AI source type) and left the eXIf block with GPS and camera, and the Author, Make, and Model text chunks. If the goal is to send the file without location, this is not enough: use All metadata.

What a clean PNG keeps: colour profile and pixel size

The PNG below carries an sRGB profile, a pixel size of 300 dpi (pHYs), a Software text, a Description, creation and modification times, and an XMP creator. We ran it in All metadata mode, then listed the result with ExifTool.

Before (what the tool listed)	After (re-scan of the download)
AI-related text (Software): Software XMP text chunk: XML:com.adobe.xmp Text chunk (Creation Time): tEXt Text chunk (Description): tEXt Modification time (tIME)	Nothing found. Banner: “Cleaned. 5 fields removed — your picture is unchanged.”

• Download: PNG, 1400x900, 2.57 MB.
• Second opinion (ExifTool 13.25): 6 metadata tags before, 0 after.
• Pixels: decoded RGB values identical to the original (compared in Python).
• Time in the tool: 241 ms in headless Chrome on a server CPU. A phone will be slower.

The profile name and the pixel size (11811 pixels per metre, which is 300 dpi) were still in the download, so colours and print size do not shift. The tool does not count them as metadata to remove.

For comparison, exiftool -all= on a copy of the same PNG printed “ICC_Profile deleted. Image colours may be affected” and left no profile and no pixel-size chunk. That is why a plain -all= is a blunt tool for PNG; the command that keeps the profile is on ExifTool remove all metadata.

Content Credentials in a PNG

A C2PA manifest in a PNG sits in a caBX chunk and can be hundreds of kilobytes. We signed a PNG with the c2pa-python library and a test certificate (so the manifest is valid but not issued by a trusted authority), cleaned it, and asked the C2PA reader to open the result:

Before (what the tool listed)	After (re-scan of the download)
C2PA (caBX): 234313 bytes AI-related text (prompt): prompt Text chunk (workflow): tEXt	Nothing found. Banner: “Cleaned. 3 fields removed — your picture is unchanged.”

• Download: PNG, 1024x1024, 2.14 MB.
• Second opinion (ExifTool 13.25): 10 metadata tags before, 0 after.
• C2PA reader (c2pa-python 0.38): manifest valid in the original, “no manifest” in the download.
• Pixels: decoded RGB values identical to the original (compared in Python).
• Time in the tool: 203 ms in headless Chrome on a server CPU. A phone will be slower.

The reader found a valid manifest in the original and none in the download. This is the file-level record only; a platform that already stored the old file still has it.

More on the manifest itself in Remove C2PA, and a read-only check in Check for C2PA.

Steps

1. Open the tool above and drop one PNG. Read the Before list; each line names a chunk.
2. Choose All metadata. Keep AI only for when you want to leave EXIF and author text in place.
3. Press Clean this file. The After list is a second scan of the new file.
4. Download the -cleaned.png. For a folder, Pro returns one ZIP; see bulk EXIF remover.

From an AI generator

ComfyUI writes prompt and workflow chunks, Automatic1111 writes a parameters chunk. Those pages explain what each tool writes: ComfyUI and Stable Diffusion.

What stays

• The pixels, including any visible or invisible watermark. SynthID and similar signals are in the image, not in a chunk.
• Copies already uploaded somewhere. Cleaning a file does not edit a page that hosts the old one.
• Not tested here: animated PNG and very large PNGs.

Questions

Does removing PNG metadata change the picture?

No. In our tests the decoded pixels of the cleaned PNG matched the original exactly (compared value by value in Python), and the file only got smaller by the size of the removed chunks: 1.956 MB to 1.955 MB on the mixed test file.

Which PNG chunks does All metadata remove?

Text chunks (tEXt, zTXt, iTXt, which includes XMP), the eXIf chunk that holds EXIF and GPS, the tIME modification time, and a C2PA caBX manifest. The tool lists what it found before it removes anything.

What does it keep?

The chunks the image needs to display correctly: the header, palette, pixel data, transparency, gamma, chromaticities, the embedded colour profile, and the physical pixel size (pHYs). The tests below check the colour profile and pHYs survive.

Why does AI only leave GPS in my PNG?

AI only targets provenance fields: AI-generator text keys, AI source type in XMP, and C2PA. On our mixed test PNG it removed four fields and left the eXIf chunk with GPS and camera, plus plain text chunks named Author, Make, and Model. Use All metadata when location matters.

Is ExifTool -all= the same thing for PNG?

It removes the same metadata, but on our PNG with a colour profile it also deleted the profile and the pixel-size chunk, and warned that image colours may be affected. The browser tool kept both. Details are on the ExifTool page.

What about animated PNG, 16-bit PNG, or very large PNGs?

This page’s measurements cover ordinary 8-bit PNGs of 1 to 2 megapixels. We did not test animated PNG specifically here. If a file cannot be read, the tool says so and does not hand back a broken download.

Can I clean a folder of PNGs?

One image is free. Pro is a one-time unlock for unlimited images and one ZIP, so a whole folder of PNGs is one run. Files stay in your browser.

Related guides

• Remove metadata from ComfyUI images
• Clean Stable Diffusion PNG metadata
• Remove XMP and IPTC metadata
• All metadata-removal guides by file type and device
• Open the Remove AI metadata tool on the homepage if you want the general cleaner.
• Short Instagram upload workflow if you only need the four-step version.