iso.tunaos.org opens on one screen: pick a desktop,
optionally change Based on, and press the one button. What the button does
depends on evidence, not preference (app/public/quick-start.js):
- Download ISO, built in your browser. The page uses this route only when two conditions are true. The catalog has a complete receipt of browser qualification for the image. This browser can build it. The browser needs WebAssembly and private browser storage. It needs at least 4 GB of device memory, when the browser reports it. It needs 9.5 GB of free storage, or 19 GB without the save dialog. The save dialog opens first. Then the build runs in the tab with the default apps of the desktop.
- Download ISO, ready-made. The page uses this route when download.tunaos.org has an ISO for the image.
- Get TunaOS Media Writer. The page uses this route when the native app
(
desktop/) has a release. The app builds the image on your computer. It also writes the USB stick. - Build on your computer. The page shows the local instructions of the full builder.
The links to ready-made ISOs and app releases come from downloads.json.
The deploy job makes this file with scripts/generate-downloads.py. The
script reads the published ISO index and the GitHub releases. If the script
cannot read a source, the page does not show that route. Thus the page never
links to a missing file.
This page shows only standard, generic x86-64 images.
Customize apps and settings (or any URL parameter, such as ?customize=1
or a share link) opens the full builder described below, on the same image.
Open the full builder (iso.tunaos.org/?customize=1) to choose any image and check whether you can build it in your browser. The build runs on your computer and saves an ISO file. You must then write that file to a USB drive to make it bootable.
- Keep Experience set to TunaOS. Other experiences can be previews with inspection and ISO creation disabled.
- Under Choose your image, use Start with a desktop or Start with a base. Answer the questions for your desktop, base, image edition and computer. The picker skips questions when only one choice remains. Follow Next: …, then Review images. Choose an available result with Use this image, or review the current Selected image. Check its computer architecture and Image details before you continue. Disabled choices show why they are unavailable.
- Leave Add your apps and Advanced settings at their defaults for a first try. App choices are request lists; they are not yet applied to the live image or installed system.
- Under Check your image, click Check image & continue to inspect the selection. This does not start an ISO download. Read the status and open Technical details for the log.
Image availability does not prove browser qualification. At the source revision checked for this guide, the catalog has no qualified browser targets. Build ISO stays disabled for those targets. If you see Browser build unavailable: …, read the reason. Build locally with tacklebox offers Download build-request.json to export the selected build request for local use. This downloads a JSON request.
See browser qualification for the evidence still required; neither inspection nor saving an ISO proves that it boots or installs.
When the status says Image inspected — ready to build. and Build ISO is enabled, click Build ISO. If you change the selection, check it again before you build. Keep the page open until the build and save finish.
- Direct file saving: The browser uses the
File System Access API(showSaveFilePicker) when available. Choose a folder and.isofilename in the save dialog. The app streams chunks of the ISO to that file. If you cancel this initial dialog, the build stops. - Browser download fallback: Without direct file saving, the app spools the ISO into the browser's private storage (OPFS). It then starts a download. Follow your browser's download prompt or settings to save it. The warning says this needs free disk space for two copies. Check the browser's downloads to confirm completion. The page cannot confirm that the download reached disk.
The warning recommends a Chromium-based browser such as Chrome, Edge or Brave. Browser storage quota and free space in the destination folder are separate limits. The app warns when the browser reports less than 9.5 GB free and blocks below 4 GB. These thresholds do not guarantee an edition will fit. Cached layers also use browser storage. When no operation is active, you can remove them under Advanced settings → Manage downloaded files → Clear downloaded layers; a later build must download them again.
The current fallback stores the ISO on disk. It does not buffer the whole ISO in memory. The WASM engine still has a roughly 4 GiB memory ceiling, even with direct saving. A build can fail in either save mode.
After ISO build complete, confirm that you have the .iso file on disk.
The page then shows options to write it to a USB drive.
This guide does not write or select a USB device.
Back up the USB drive and check the target before you write media. The drive must have more space than the ISO file. With normal installation, Ventoy formats the selected drive and erases its data.
If Ventoy is already installed, copy the ISO to its data partition; do not reinstall Ventoy to add a file. Check that the partition has enough free space. Follow the selected edition's official media instructions.
Open an iso-builder issue with your browser name and version, operating system, selected desktop/base/ edition and target architecture, and the steps that failed. Include the exact status/error and relevant Technical details log lines. Say whether you used the save dialog or browser download, whether the download completed, and any reported storage quota or memory warning. Review logs and screenshots before you post them; remove tokens, credentials, private URLs and personal paths.
We compared control labels and save/storage behavior with
index.html, app.js,
guided-picker.js and
builder-config.json at d2521c7.
We checked relative links. We did not run a full ISO build, USB write or
installation to validate this guide.
ISO saved means the writer closed the file without an error.
Download started means the browser accepted a download request.
The page cannot confirm that the download finished or that the file persists.
Check the download list in your browser before you write media.
If a user cancels a save, or a write fails, the page must hide the installation card. Neither message proves a checksum match, publisher identity, or a successful installation.
The page must show unknown quota as unknown. App choices are requests; the engine does not apply them to the system.
The first screen uses the recommendation in the deployment configuration. It never selects the first catalog entry as a substitute. Qualification remains separate. The page does not replace unavailable targets.
Use Help me choose / browse all setups to open catalog choices.
The base-first and desktop-first paths use the same catalog.
Check the architecture of the installation target, not the browser host.
Before you create media, review the target, temporary storage needs, and limits for app requests. Back or Escape keeps the form unchanged. On phones, use the setup link to move supported choices to a desktop. The link does not use cloud storage.
This stage does not restore unsaved changes after refresh. It does not import TOML setups.
The guidance for USB writers depends on the experience.
The Bluefin preview links to its official
installation runbook.
On 2026-11-02, that guide recommended Fedora Media Writer and did not support Ventoy.
Use that guide for upstream media. This preview cannot create an installable Bluefin ISO.
Use Save planning choices for a refresh to save a plan in this tab's session storage.
You must select the restore action explicitly.
The action checks the version, experience, catalog identity, selected leaf and each filter against the current catalog.
It keeps only catalog choices, app requests, package names and an uppercase ISO label.
The restore action does not restore build readiness, receipts or notice acknowledgements.
Advanced images, commands and overrides for boot or connections prevent a save or restore.
The action does not silently drop these values.
Use Forget saved plan to clear stored data. It does not clear the current form.
If storage fails, the form stays unchanged. This temporary UI state is not a separate configuration source or a portable TOML format.