ComfyUI Workflow JSON PNG Chunks

July 4, 2026

What lives in PNG text chunks

Unlike EXIF in JPG, chunk data sits beside the image stream:

Full workflow graph (node IDs, links, weights)
Seed, steps, cfg parameter strings
Optional prompt fragments

Instagram still uploads read the container . A flattened preview PNG exported without "Save (API)" discipline often still contains chunks from the graph that produced it.

Export settings that reduce chunk load

Prefer Save Image nodes that write flat JPG for social when quality allows. If PNG is required for transparency, run chunk removal on the upload master - not a screenshot of the ComfyUI canvas.

Output

Chunks

Social default

ComfyUI PNG (default Save)

Heavy

Strip before upload

JPG from VAE decode node

Usually lighter

Still check XMP

PSD/ TIFF archive

N/A internal

Never upload raw

Pair with Flux & ComfyUI Instagram guide when Flux checkpoints drive the graph.

Chunk removal vs EXIF-only tools

Desktop EXIF strippers often ignore PNG ancillary text . Browser remover with PNG chunk toggle targets exactly what ComfyUI writes. Checker first: if you see parameters or workflow keys, EXIF-only passes fail.

Cross-platform posting

Cleaned PNG/JPG masters can feed Instagram , Pinterest , and LinkedIn document posts if you upload identical bytes . Discord/Telegram forwards before upload re-encode - avoid.

Do not publish workflow JSON inside PNGs to social - strip on the Flux upload hub before any Instagram or TikTok still upload.

Node graph hygiene for social teams

Standardize one Save Image subgraph for all freelancers - reduces chunk variance. Document forbidden nodes that embed debug JSON in PNG output.

SDXL vs Flux chunk differences

Chunk keys differ by checkpoint pipeline - checker spot when switching models mid-campaign. Do not reuse strip profile from SD1.5 week for Flux week blindly.

TikTok still cross-post

Same cleaned PNG works for TikTok photo mode if bytes match - TikTok ingest also reads containers; strip before multi-platform drop.

"Save (API)" vs preview PNG

ComfyUI Save Image nodes differ - some embed full graph JSON, others minimal parameters only. Checker the node you actually wire to Instagram carousels.

Batch same graph week

When one workflow feeds ten PNGs, one checker read on slide 1 usually sets toggles for all - unless you change checkpoint mid-batch.

Custom node audit

Community custom nodes sometimes inject debug PNG metadata - whitelist nodes for social export graphs before freelancers ship overnight batches.

See Stable Diffusion / ComfyUI hub , strip on the Flux upload hub , then upload to Instagram .

See Disclaimer .