A local front end for ComfyUI.
28 model families work out of the box, and your own ComfyUI workflows come along. Write a prompt and watch it render.

Quick start  ·  Models  ·  Inpainting  ·  Workflows  ·  Help  ·  FAQ

_{Free and open source under MIT. Built on J-AI Studio by Jasper.}

HEISS UI sits on top of the ComfyUI you already run. You get a prompt box, a gallery and the settings that matter for the model you picked. ComfyUI still runs every job and keeps your nodes, models and outputs.

The node graph is for building workflows. HEISS UI is for the everyday loop of prompt, wait, look, tweak, and your workflows come along.

• 28 model families, ready to go. From SD 1.5 and SDXL to Flux.2, Qwen-Image, Krea 2 and Wan 2.2, each with its makers' recommended settings. The full list ↓
• Missing parts, one click away. Pick a model and see what it still needs, with a Download button for each part and Get all for the lot.
• Smart upscale. Pick 2K or 4K and every new picture comes out bigger and sharper, with a countdown. Any older picture upscales in one click.
• Bring your own workflow. Import a ComfyUI workflow and it becomes a clean set of controls, with your graph running underneath. How it works ↓
• Inpainting (beta). Paint over part of a picture, say what it becomes, and only that part changes. No extra nodes, and it works with 18 image families.
• Auto-grouping. Ten takes of one idea become one tile, so a gallery of hundreds stays easy to scan.
• On your phone and every device. A phone layout made for one thumb, and the full studio on any laptop or tablet on your network. Your PC renders, and every device shares the same models and gallery. Set it up ↓
• Hidden. A locked place for images you keep to yourself, opened with Touch ID, Windows Hello or a password. Generate into it, or hide anything later.
• Civitai-ready images (beta). New PNGs carry their prompt and settings in a form Civitai fills in for you on upload. Turn it on in Settings › Library.
• Zen mode. Just the prompt and the picture, fullscreen.

LoRA stacks, live previews, video previews, recent prompts and gallery search are on the website.

1. Download the zip for your system from the latest release:

The plain heiss-ui-*.zip (no system in its name) is for in-app updates; you can skip it.

2. Unpack it and double-click Start HEISS UI (.bat on Windows, .command on macOS, .desktop on Linux), or run npm start in the folder. Node.js and the packages are inside, so there's nothing else to install, and the studio opens in the browser.

3. Have ComfyUI running. ComfyUI on this computer connects automatically, at http://127.0.0.1:8188 or ComfyUI Desktop's port 8000. On another machine or port, set its address in Settings › Connection.

Launcher won't open, or the window closes? Troubleshooting › Starting HEISS UI covers macOS, Windows and Linux. To hand the whole setup to a coding agent (Claude Code, Codex), the install section has a prompt to paste.

git clone https://github.com/tristmeister/HEISS-UI.git heiss-ui
cd heiss-ui
npm install
npm start

28 families run out of the box with their makers' recommended settings, and a renamed file is still recognized.

Image (21): Krea 2, Anima, Z-Image, Flux.2 (Dev, Klein 4B, Klein 9B), SDXL (NoobAI, Illustrious, Pony and more), Pony V7, Chroma, Qwen-Image (and 2.1), Ideogram 4, MageFlow, ERNIE-Image, Lumina Image 2.0, Sana, HiDream I1, SD 3.5, Flux.1, SD 2.x and SD 1.5.

Video (7, beta): MiniMax H3, HunyuanVideo 1.5, Wan 2.2 (5B and 14B) and Wan 2.1, with text and image to video where the model has both.

Missing parts get a Download button. An unrecognized file can be given a type under Settings › Models › Model types. GGUF files work; Nunchaku, NF4 and other formats that need their own loader nodes don't (formats). Anything else runs as your own workflow.

The built-in models cover the everyday loop. For anything custom, bring your graph.

1. Export. Build and test the graph in ComfyUI, then export it (API format works best; the regular workflow file works too).
2. Drop. Open the Workflow Gallery from the dock and drop the file on it, or paste the JSON.
3. Check the connections. The usual inputs are connected for you. Change any of them under Change connections, then import.

The workflow shows up in the model menu under Your workflows once the nodes it needs are installed.

The usual inputs (prompt, size, seed, steps and the like) are connected for you, and only those change; everything else runs as exported. The review marks anything it guessed, warns about nodes that run code, touch files or go online, and tells you where a missing model file belongs, with a Download button when it knows the file. To ship a workflow with its connections fixed, see the workflow guide.

Getting a new model running in ComfyUI usually means hunting for the right text encoder, the right VAE and a custom node pack or two. Here each part gets a button, and Get all fetches the lot. Nothing downloads until you press the button. What's covered.

• Reference images for edit models. Flux.2 (Klein 4B, Klein 9B and Dev) and Qwen-Image 2.1 edit from reference images.
• Start images for everything else. Every other built-in image model (Krea 2, SDXL, Flux, Z-Image and the rest) offers Add start image. The image then sits in the sidebar's Basics with Change from the reference right under it, for how far the result may move from it.
• Paint on either one. Hover a reference or start image and press the brush to inpaint just part of it.

Change one part of a picture and keep the rest. Hover a reference or start image in the prompt bar and press the brush, paint over what should change, then write what it becomes.

• The rest stays untouched. Only the painted part is redrawn, so the rest never softens or shifts in color.
• Works with your models. 18 of the 21 image families inpaint, with no extra nodes. The model menu marks which ones.
• A proper brush. Brush, eraser, hand, undo, zoom and size, on a phone too.
• Two dials. Inpaint strength and Edge softness sit under the image in the sidebar (in the Advanced sheet on a phone).

Not for Ideogram 4, MageFlow, Sana, video or imported workflows, and there's no outpainting or layers. Inpainting is in beta and on by default; Settings › Features › Inpainting turns it off.

Bigger, sharper pictures with SeedVR2, without leaving the studio.

• 2K or 4K for every new picture. Pick None, 2K or 4K next to the size menu (on the phone, in the create sheet). The upscale is part of the run, so you can close the page and it still finishes. The next run waits for it, and if you stop it or it fails, you keep the picture at its generated size.
• Any picture, one click. The upscale arrow on a tile or in the viewer upscales anything already in the gallery, Hidden included. The upscale is saved next to the original, and a slider drags across both to show what changed.
• Time left, not a spinner. The ring, the buttons and the queue count down the seconds that are left.
• Set up when you need it. Picking 2K or 4K without the SeedVR2 nodes or model offers to install them, with sizes shown before anything downloads.

Making ten takes of one idea fills a gallery fast. With auto-grouping on, pictures from similar prompts, even ones you tweak as you go, fold into one tile once you stop working on them.

• Stacks with a count. A stack shows as a photo with two edges under it, or as a cover flow, with the number of pictures in the corner.
• Skim without opening. Slide the pointer along the bottom of a stack to flip through it. Open it to spread the pictures out, or Unstack to keep them apart.
• It follows your prompts. Similar prompts group together, and coming back to a prompt the next day starts a new stack.
• Your files stay put. Grouping changes no files. Switch it off and the gallery is as it was.

Turn it on with the stack button next to gallery search, or under Settings › Library › Auto-grouping, where you also pick the photo or cover-flow look.

On a phone the studio switches to its own layout. Prompt, browse, share and upscale while your PC renders.

Set up LAN access first, then scan the QR code shown in Settings › Connection with your phone and sign in. Both devices need to be on the same trusted network.

Use a laptop, tablet, phone or another desktop on the same local network to prompt, browse the gallery and upscale. HEISS UI and ComfyUI keep running on your PC with its models and outputs; the other device needs only a browser.

1. On the PC running HEISS UI, open Settings › Connection and turn on Open on other devices.
2. In the same settings, set a studio password under Signing in.
3. On your other device, open the network address shown in Connection (for example, http://192.168.1.20:8787) and sign in with that password. Use your PC’s listed address, not localhost.

Laptops and desktops get the full studio and phones get the phone layout. Only enable access on a network you trust. Admin controls stay at the PC unless you allow them for signed-in devices.

Signing in, admin rights, HTTPS and proxies are covered in SECURITY.md.

Hidden is a place for the images you'd rather keep to yourself. Open it from the lock in the dock. The first time, it walks you through a password and, where the browser supports it, Touch ID or Windows Hello.

• Generate straight into it. Anything made while Hidden is open renders there, with the same live previews, and stays out of the gallery.
• Hide from the gallery. The eye on a tile (or in the viewer) moves an image into Hidden, or back out. Upscale, compare, remix and video all work inside it.
• Locked means out of sight. A locked Hidden shows no thumbnails and no count, and its prompts stay out of Recent prompts. It locks after a while without activity (Settings › Hidden › Auto-lock), or right away with Lock.

Images, prompts, settings and upscales in Hidden are encrypted on disk with a key that only your password or a passkey can open, and ComfyUI's own copies are removed. Hidden keeps things out of casual view; it isn't forensic-grade protection. SECURITY.md has the details, including what passkeys need.

There's no password reset. If the password and every passkey are lost, Erase Hidden in Settings › Hidden starts over and takes everything in Hidden with it.

Settings › About › Install update updates a downloaded release in place, and a Git checkout too as long as it has no local changes. A downloaded release also offers new versions in a small pill at the top.

Updating a checkout by hand is in Troubleshooting.

Copy .env.example to .env when you need different ports or paths.

COMFY_URL=http://127.0.0.1:8188
HOST=127.0.0.1
PORT=8787
HEISS_DATA_DIR=./data
COMFY_OUTPUT_DIR=

Everything else (the output folder, other devices, HTTPS, the Hugging Face token, proxies) is in CONFIGURATION.md.

A Windows shortcut that starts ComfyUI and HEISS UI together is in WINDOWS-SHORTCUT.md.

TROUBLESHOOTING.md covers the common problems. A failed generation links straight to its section.

• No models showing up? Make sure ComfyUI is running. On this computer it connects on port 8188 or 8000; anywhere else, set its address in Settings › Connection. After adding files, use Settings › Models › Rescan.
• Asking for help? Settings › About › Copy diagnostics copies versions, system and GPU, without prompts or images. Paste it on the board or in the Discord.

Found a bug, want a feature, or not sure how something works? Post it on the feedback board: it's public, needs no account, and shows what's planned, in progress and done. Rather talk it through? Join the Discord.

From the app, Idea or bug? at the bottom of the Settings sidebar and Report bug on a failed generation send a post with the details filled in, and you see everything that goes with it before you send. GitHub issues work as well.

The website FAQ answers the common questions.

npm install
npm run dev

npm run dev starts Vite and the local API server together, and npm test runs the server and script tests. Adding a model family is mostly data: MODELS.md walks through it. Contributions are welcome. See CONTRIBUTING.md, and leave generated media, model files, logs and .env files out of commits.

HEISS UI started as a fork of J-AI Studio by Jasper. The prompt-first idea and much of the foundation are his work. If HEISS UI is useful to you, go give the original a star too.

Built on ComfyUI.

MIT. The original J-AI Studio copyright notice is kept alongside HEISS UI's, as the license asks.

The downloads include an FFmpeg build (via ffmpeg-static) for video previews. It's licensed separately under the GPL, with its license and source at those links.