PNGCHUNKS(1)

📦
version 1.2 · 7 versions
, in ubuntu stonking

💅 PNGCHUNKS(1) — the manual page, but make it cute

okay so bestie, listen. this is the manual page for pngchunks, part of the User Commands squad. it's short, it's sweet, it's giving "tiny tool, big brain" energy, and i'm about to walk you through every single crumb of it. no skips, no cuts. periodt. ✨

🌸 NAME 🌸

pngchunks — print information embedded into a PNG file 🖼️✨

like. it reads your PNG and tells you what's inside it. the hidden lore. the chunk gossip. iykyk.

🎀 SYNOPSIS 🎀

pngchunks

yeah that's it. that's the whole synopsis. no flags, no args in the synopsis line, just the raw unhinged confidence of a program that simply exists. she's low maintenance. 💅

🦋 DESCRIPTION 🦋

pngchunks is a program that displays informations from files created according to the Portable Network Graphics file format.

that's it. that's the description. one sentence and honestly? it ate. it tells you exactly what you need: this thing shows you the information that lives inside PNG files. the chunks. the metadata. the little secrets. 🔍💖

🌈 EXAMPLE 🌈

here's what it looks like when it's doing its thing, bestie. watch and learn:

              pngchunks input.png Chunk: Data Length 13 (max 2147483647), Type 1380206665 [IHDR]
                Critical, public, PNG 1.2 compliant, unsafe to copy
                IHDR Width: 256
                IHDR Height: 256
                IHDR Bitdepth: 8
                IHDR Colortype: 2
                IHDR Compression: 0
                IHDR Filter: 0
                IHDR Interlace: 0
                IHDR Compression algorithm is Deflate
                IHDR Filter method is type zero (None, Sub, Up, Average, Paeth)
                IHDR Interlacing is disabled
                Chunk CRC: -753909967 Chunk: Data Length 6 (max 2147483647), Type 1145523042 [bKGD]
                Ancillary, public, PNG 1.2 compliant, unsafe to copy
                ... Unknown chunk type
                Chunk CRC: 554438993 Chunk: Data Length 9 (max 2147483647), Type 1935231088 [pHYs]
                Ancillary, public, PNG 1.2 compliant, safe to copy
                ... Unknown chunk type
                Chunk CRC: -757235972 Chunk: Data Length 7 (max 2147483647), Type 1162692980 [tIME]
                Ancillary, public, PNG 1.2 compliant, unsafe to copy
                ... Unknown chunk type
                Chunk CRC: 429243611 Chunk: Data Length 831 (max 2147483647), Type 1413563465 [IDAT]
                Critical, public, PNG 1.2 compliant, unsafe to copy
                IDAT contains image data
                Chunk CRC: 1406256926 Chunk: Data Length 0 (max 2147483647), Type 1145980233 [IEND]
                Critical, public, PNG 1.2 compliant, unsafe to copy
                IEND contains no data
                Chunk CRC: -1371381630

so like — IHDR gives you the deets: Width, Height, Bitdepth, Colortype, Compression, Filter, Interlace, plus whether the Compression algorithm is Deflate, whether the Filter method is type zero (None, Sub, Up, Average, Paeth), and whether Interlacing is disabled. 👑

then you get bKGD, pHYs, tIME — all hanging out saying "... Unknown chunk type" like they're strangers at a party 😭 — then IDAT doing the heavy lifting ("contains image data"), and IEND wrapping it all up ("contains no data"). every single one of them gets a Chunk CRC, and each chunk's tagged as Critical/Ancillary, public, PNG 1.2 compliant, and either safe to copy or unsafe to copy. the details!! i'm obsessed. 🔥

🫶 SEE ALSO 🫶

go read the whole friend group:

⭐ VERSION ⭐

This documentation is for pngtools 1.0.

👑 AUTHOR 👑

pngtools was written by Michael Still and is released under the GNU GPL.

The project is hosted at https://github.com/mikalstill/pngtools. 🌐

💀 BUGS 💀

found something cursed? please report bugs at:

https://github.com/mikalstill/pngtools/issues

bestie do NOT suffer in silence. if it's broken, tell them. 🫶

and that's the whole page!! this one's a User Commands classic, dated 10 June 2026, and it's literally all documented above, nothing left out, no crumbs dropped. go forth and chunk-spot 🧚💜 bye bestie!!

📦 where this page comes from