Drop a PNG here
or click to choose
processed in your browser · never uploaded
Drop or click to replace
Metadata fields
An editor that writes text metadata (tEXt / iTXt chunks) into a PNG. You can embed a prompt, negative prompt, seed, sampler and other settings under the same "parameters" keyword that AUTOMATIC1111 (A1111) uses, or leave a comment, title or author under any keyword you like (Comment / Description / Title / Author …). When you load an image, any existing text metadata is read straight into the fields, so it works as a true read → edit → write-back editor. Writing is lossless: it never touches the pixel data (IDAT), inserts the new chunks right before IEND, and recomputes the CRC so viewers won't flag the file as corrupt. Existing metadata under the same keyword is replaced, so you never get duplicates, and any text that can't be represented in Latin-1 (such as Japanese) is stored in a UTF-8 iTXt chunk. It's the exact inverse of reading generation info with "PNG Info" — handy when you want to write a prompt back into an image that lost it during a re-upload or edit, or stamp a source/license onto an image you're sharing. Because prompts can be sensitive, this tool never uploads your image; all processing happens locally in your browser.
How to use
- Drop a PNG in or click to choose a file (PNG only). Any existing metadata loads into the fields automatically.
- Enter a keyword (e.g. parameters / Comment / Author) and its value. Use the "Quick add" chips or "Add field" to add more rows.
- Click "Download PNG with metadata" to save. Pixels stay untouched and existing metadata under the same keyword is overwritten.
FAQ
Is my image uploaded to a server?
No. All chunk writing happens in your browser. Your image is never uploaded, stored, or sent anywhere — it's processed only on your device, so it's safe even when you don't want to expose your prompts.
Does it reduce image quality?
No. This is a lossless operation. It never touches the pixel data (IDAT); it only adds text chunks before IEND. Nothing is re-encoded, so image quality is unchanged.
Will viewers like AUTOMATIC1111 read it as generation info?
Yes. Set the keyword to "parameters" and enter an A1111-style body (prompt, then a line starting with Negative prompt:, then a settings line like Steps: …). PNG Info viewers will recognize it. You can verify with the "PNG Info" tool on this site.
What happens if I use the same keyword twice?
When writing, any existing text chunk (tEXt / zTXt / iTXt) with the same keyword you're adding is removed first, then the new value is written. So it overwrites (replaces) rather than leaving duplicate chunks.
Can I add Japanese or other non-Latin comments?
Yes. Any value containing characters that can't be represented in Latin-1 (such as Japanese) is automatically stored in a UTF-8 iTXt chunk. Note that the keyword itself is limited to Latin-1 by the PNG specification.
Can it write into JPEG or WebP?
No. This tool is for PNG tEXt / iTXt only. It does not write EXIF into JPEG / WebP. To read generation info use "PNG Info", and to strip metadata use the "Clean Metadata" tool.