Read the generation parameters actually stored in a PNG

Get an actual original with known text

Use the historical ControlNet example linked below, or an original PNG you are allowed to inspect. On Commons choose Original file, not the resized page preview or a screenshot. Our checked original is 1024 × 688 pixels and 977646 bytes, with one tEXt field named parameters. Its exact text has 508 characters and matched an independent Pillow 12.3.0 reading.

The source page supplies the example's attribution and context. The viewer reads its editable saved fields; it does not verify who generated the picture, authenticate a model name or produce an AI-classifier score from those values. Keep the original-file role clear when comparing it with an export or screenshot.

• Historical ControlNet PNG on Wikimedia Commons — Commons attributes the 2023 example to Automatic1111 and lists it as public domain. Use Original file, not a preview. The checked file has one 508-character parameters field; attribution and stored metadata are not authenticated by this reader.
• Download the self-authored parameters PNG — Project-authored 1 × 1 PNG with five text fields: Author, Software, parameters, workflow and prompt. The 159-character parameters text contains the exact seed 9223372036854775807; this is a format fixture, not an A1111 generation.

Read, parse and save one actual field

1. Step 1

   Choose the original in the local PNG reader

   Open Stable Diffusion PNG info and use Choose a PNG for local metadata reading. Select the ControlNet original. Expect one text field, parameters, with tEXt storage and the original dimensions. The local reader does not decode image pixels or upload this input.

   Open the local PNG parameters reader

2. Step 2

   Inspect the raw text before interpreting it

   Expand parameters. The text includes Steps 20, Sampler DPM++ 2M Karras, CFG scale 7, Seed 1459289660, Size 1024x688 and a quoted ControlNet 0 value. Preserve the quoted extension setting instead of splitting every inner comma into a new top-level setting.

3. Step 3

   Open the parsed view from this same field

   Click Parse stored parameters. The parsed panel separates positive prompt and the recognized settings; no second upload is needed. The source has no Negative prompt marker, so the panel reports that absence rather than fabricating a negative prompt or default seed.

4. Step 4

   Save the exact original text

   Use Copy field and Download text on the original field, or Copy original parameters and Download original parameters in the parsed panel. The field download is png-field-1.txt; the parsed-panel original download is original-parameters.txt. Both should retain the same 508 characters. Keep settings whose meaning is unknown with the original.

Check the self-authored precision control

Choose a1111.png below, or use Try synthetic PNG sample in the PNG reader. This different file is a project-authored 1 × 1 fixture with five fields, not a generated ControlNet image. Its parameters field has 159 characters: the seed is exactly 9223372036854775807, steps 20, CFG 7, sampler Euler and model example-model.

Click Parse stored parameters for that occurrence and compare Seed (exact string) with the original text. The seed must not become a rounded neighboring integer. The extra workflow and prompt fields belong to their own JSON representations; parsing parameters does not convert them or execute a workflow.

• Download the self-authored parameters PNG — Project-authored 1 × 1 PNG with five text fields: Author, Software, parameters, workflow and prompt. The 159-character parameters text contains the exact seed 9223372036854775807; this is a format fixture, not an A1111 generation.

Try missing text and a failed read separately

Choose empty.png. The PNG is valid but contains no embedded text fields, so no parameters can be recovered from it. A PNG may also contain other text, or only a ComfyUI prompt, without an A1111 parameters field. That is different from a corrupted or unsupported input.

The reader checks PNG signature, chunk boundaries and CRCs. A renamed JPEG, failed CRC, unsupported browser decompression or exceeded limit has a visible failure instead of a successful no-parameters conclusion. PNG limits are 10 MiB, 32 text fields, 256 KiB per field and 1 MiB total decoded text; embedded JSON has additional bounded traversal limits.

Before sharing a field export, read it for private prompt text, file paths, names and extension values. This local reading does not make those exports safe to post, certify a model hash or guarantee that the stored values can reproduce the image.

• Download the PNG without stored text — A defined metadata-free version of the same project-authored 1 × 1 pixels. No parameters or workflow are inferred from its image data.
• Choose a next step when parameters are absent — Separate known local removal from an unknown file history.

Sources and reproducible inputs

• Historical ControlNet PNG on Wikimedia Commons — Commons attributes the 2023 example to Automatic1111 and lists it as public domain. Use Original file, not a preview. The checked file has one 508-character parameters field; attribution and stored metadata are not authenticated by this reader.
• Download the self-authored parameters PNG — Project-authored 1 × 1 PNG with five text fields: Author, Software, parameters, workflow and prompt. The 159-character parameters text contains the exact seed 9223372036854775807; this is a format fixture, not an A1111 generation.
• Official A1111 infotext parser, fixed revision — Reference 82a973c04367 for saved-generation text syntax. Our local parser preserves the original and unknown settings; it does not execute upstream code or apply upstream defaults/styles.
• W3C PNG Third Edition, 24 June 2025 — Fixed primary reference for PNG chunks and text storage. A stored field is editable data, not proof of a generator or a signature.