ISO maker — folder to disc image

Tool for creating ISO disk images directly in your browser. Pick a folder, set a volume label, optionally add a boot image — and download a standards-compliant ISO9660+Joliet image. With the hybrid MBR option the result also boots from a USB stick written with `dd`.

How to build an ISO

Pick a folder

Click "Pick folder" to open the system folder picker, or use Add files to assemble a manual list.

Set the metadata

Enter a volume label (max 32 chars) and optional publisher.

Add boot image (optional)

Drop a BIOS/UEFI boot image and tick Hybrid MBR if you want a USB-bootable ISO.

Pick output destination

showSaveFilePicker opens; choose where to save the ISO.

Build

The image streams to disk; progress shows the build phase as it runs.

Pack any directory into a downloadable ISO disk image

Drop files here or click to browse

Any files

Volume label Publisher

Joliet (Unicode long names) Hybrid MBR (USB-bootable)

Why this builder is special

Bootable ISOs

Add a BIOS or UEFI boot image and we emit a valid El Torito boot record plus an optional ISOHybrid MBR so the output boots from CD/DVD and dd-written USB sticks.

Folder picker

Pick any local folder via the File System Access API; subdirectories, long names and Unicode are handled. Or drag a folder onto the zone.

Streamed 8 GB+ output

The ISO is written sector by sector to a file you choose with showSaveFilePicker; 8 GB output works on a 2 GB-RAM phone because nothing is buffered.

Joliet long names

Long Unicode names via Joliet (UCS-2BE) are added automatically when source filenames need them; standard ISO9660 8.3 names ship in parallel for compatibility.

Pre-build estimate

Before generation, see the estimated output size, file count and how many names will need Joliet long-name encoding.

Volume metadata

Set the volume label, publisher and application identifier so disc-writing tools and OS installers show the correct label.

ISO creator — common questions

Will my ISO boot from a USB stick?

Yes, when you provide a boot image and tick Hybrid MBR. The output gets a valid El Torito record (for BIOS/UEFI from optical media) and a hybrid MBR so dd if=image.iso of=/dev/sdX produces a bootable USB.

Can I include files larger than 4 GB?

Files larger than 4 GB are stored as multi-extent records; ISO9660 alone caps single-file size at 4 GB so very large files may need UDF for some readers.

Is there an output size limit?

No. The ISO streams to disk via the File System Access API; only your free disk space matters.

Are filenames case-preserving?

Yes when Joliet is enabled. Joliet stores the original Unicode names case-preserved; ISO9660 also has 8.3 forms for legacy compatibility.

Is my folder uploaded to a server?

Building runs as JavaScript in your browser tab — the page reads bytes from your local files using File.slice() and writes the result via the File System Access API, so the build itself does not need an upload. The page, your rating and basic anonymous usage events are served from and reported to our servers; the contents of your folder are not part of those events.

Can I rebuild an ISO from a slightly modified folder?

Yes. Pick the modified folder, keep the same volume label, and build again. Future versions will include a diff-and-update mode that preserves the original PVD metadata.

Will my ISO open on macOS / Linux / Windows?

Yes. ISO9660 is supported by every major operating system; Joliet adds Windows-friendly long names; Linux mounts the result with mount -o loop.

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Who is this tool for?

Published 08 May 2026 Author: The Supreme