Overview
Introduction
This tool strips a PNG down to only the chunks required to render it, removing every ancillary piece of metadata in one pass, entirely in your browser.
It's the more thorough counterpart to PNG Text Remover: instead of targeting just text chunks, it removes all non-essential metadata at once.
What Is PNG Metadata Eraser?
A byte-level PNG chunk filter that keeps only IHDR, PLTE, tRNS, IDAT, and IEND — the chunks that actually determine how the image decodes and renders — and drops everything else.
It reports back exactly which chunk types it removed, so you can see precisely what metadata the file was carrying.
How PNG Metadata Eraser Works
The uploaded bytes are walked chunk by chunk after the 8-byte PNG signature, checking each one's 4-byte type code against a fixed allow-list of render-critical chunk types.
Allow-listed chunks are copied through unchanged; every other chunk is omitted from the output and its type code is recorded in the removed-chunk-types list returned to the caller.
When To Use PNG Metadata Eraser
Use it before publishing or sharing a PNG when you want to strip any potentially identifying or extraneous metadata — timestamps, software credits, color profiles, EXIF data — in a single step.
It's a good privacy-hardening pass for user-uploaded images or screenshots that might carry more metadata than you realize.
Often used alongside PNG Text Remover, PNG Text Extractor and PNG Metadata Changer.
Features
Advantages
- Runs entirely client-side; the uploaded file is never sent to a server.
- Removes all ancillary metadata categories at once, not just text.
- Leaves the rendered image completely unchanged, since only non-rendering chunks are dropped.
Limitations
- This is an all-or-nothing strip of ancillary metadata; if you want to keep some fields (like a color profile) while removing others, use PNG Text Remover or PNG Metadata Changer for more targeted control.
- Dropping the color profile (iCCP/sRGB) chunk means color-managed viewers will fall back to assuming standard sRGB, which is usually fine but can shift color slightly for images authored in a different color space.
Examples
Best Practices & Notes
Best Practices
- Run this as a final step before publishing user-generated or camera-sourced PNGs to strip incidental metadata.
- If you need to keep a color profile intact, use a more targeted tool instead of this all-in-one eraser.
Developer Notes
The lib function is a pure chunk-stream filter operating on a Uint8Array: it maintains a small allow-list Set of render-critical chunk type names (IHDR/PLTE/IDAT/IEND/tRNS), copies allow-listed chunks through byte-for-byte, and collects every other chunk's type code into a removedChunkTypes array instead of writing it to the output.
PNG Metadata Eraser Use Cases
- Stripping EXIF and other identifying metadata from user-uploaded images before storage
- Cleaning up screenshots or exports that accumulated timestamps and software credits
- Reducing file size slightly by dropping unnecessary ancillary chunks
Common Mistakes
- Expecting selective removal — this strips all ancillary metadata at once, not just one field.
- Not realizing a dropped color profile chunk can cause a very slight color rendering shift in color-managed viewers.
Tips
- Run PNG Text Extractor first if you want to see what metadata exists before erasing it.
- Use PNG Metadata Changer afterward if you still want to add back a single intentional field like an author credit.