A fireplace that crackles, with no video file at all.
The flame is computed frame by frame and the crackle is synthesized on the spot — no assets, no streaming, no loop to notice. One dial takes it from embers to a blaze, and every pop you hear flares in the flame you see.
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One dial, from embers to a blaze.
Light it and it burns. The only real control is Intensity, and it moves the whole fire at once: the height the flame reaches, how often it crackles, how many sparks come off the top, and how much low-end body the sound has. Turn it down and you get embers ticking over; turn it up and you get a proper blaze. There is a volume slider and a mute, and that is the entire interface — a widget you install to relax should not arrive with a mixing desk.
It sits in the popover like any other widget, and it also opens in its own window, which is where most people leave it. Whether it is lit is remembered, so reopening it brings back a burning fire rather than a cold one. The flame also tracks the shape of whatever it is drawn into, so it does not get squashed in the narrow popover or stretched thin in a wide window.
- One intensity dial: flame height, crackles, sparks and sound together
- Volume and mute; nothing else to tune
- Stays lit between sessions
- Its own window at 420×480, or immersive fullscreen
- Sound keeps playing with the popover closed; the animation pauses
A fireplace that crackles and moves, generated on the fly: no files, no connection, and no two flames alike.
Light itBoth the picture and the sound are made up as they go.
The flame comes from a heat simulation: a grid where heat is seeded along the bottom and propagates upward while it decays, which is the trick that gave 1990s games their fire. That small grid is scaled up smoothly and given a bloom, then logs, pulsing embers and sparks go on top. Because the grid follows the aspect ratio of whatever it is being drawn into, the fire keeps its proportions at every size.
The sound is built the same way. A bed of brown noise through a filter gives the low roar; each crackle is a short burst of noise pushed through a narrow filter with a fast decay. The crackles arrive at random intervals rather than on a timer, because a fixed interval is instantly recognisable as a metronome and your ear will not let it go.
Then the two are wired together. Each audible pop injects heat at the base of the fire, so the flare you see is the crackle you just heard. And a note on how those numbers were chosen: the decay rate, the width of the base and the flicker frequencies came from rendering frames and looking at them, not from theory. Three earlier attempts produced a wall of embers, horizontal stripes, and a smooth featureless dome.
- Flame from an upward-propagating heat grid, scaled and bloomed
- Sound from filtered brown noise plus generated crackles
- Crackles at random intervals — no metronome
- Every pop you hear flares in the flame you see
- Keeps its proportions from popover to fullscreen
Fullscreen means the fire, not the fire plus a control panel.
Press ⛶ and the fire takes the whole window. The controls do not get a strip along the bottom — they float over the flame and then fade out after a couple of seconds of you not moving the mouse, exactly like a video player. Move the mouse and they are back.
It does not trap you: any movement brings the controls back, and Esc always exits. The immersive treatment applies to the fire in its own window only — in the popover, where the widget shares space with your other tiles, it stays a tile.
- The fire fills the window; controls float above it
- Controls fade after ~2.6 s of no mouse movement, and return on any
- Esc always exits — no trap
- Its own window only; the popover tile stays a tile
A ten-hour video is still a loop with ads in front of it.
The usual way to get a fire on your screen is a long video: a browser tab open all afternoon, an ad before it starts, another one an hour in, a fan spinning up to decode 4K you are not looking at directly, and a loop point you will eventually spot. Dedicated fireplace apps solve the ads but bring hundreds of megabytes of footage — and the loop.
This is a few kilobytes that never repeats, in the same popover as the rest of your widgets, with no tab to lose and nothing to stream. What it is not is photorealistic: it is a stylised fire, not 4K footage of real logs. If what you want is a beautiful video of a real fireplace, a video is the right tool. If what you want is a fire in the corner of your screen that you never have to think about, this is it.
- No tab, no ads, no buffering, no loop
- Works on a plane, or with the Wi-Fi off
- Stops rendering when you are not looking at it
- Honest limit: stylised, not photorealistic footage
Installed from the catalog, in one click.
Fireplace isn’t bundled into the app — it’s a widget in the Webstarted Toolbox catalog. Download Toolbox, open the catalog tab (🧰), press the “+” next to Fireplace, and it lands in your Fun tab. Here are a few of its neighbors:
Questions, answered.
Is this a video of a fireplace?
No — there is no video and no audio file anywhere in it. The flame is computed frame by frame from a heat simulation, and the sound is synthesized: a filtered noise bed for the body of the fire, plus individual crackles generated as short noise bursts. That is why the whole widget is a few kilobytes instead of a few hundred megabytes, works with the network off, and never loops. No two minutes of it are the same.
Why does it matter that it doesn’t loop?
Because a loop is the thing that breaks the illusion. Every fireplace video, however long, eventually repeats — and once you have noticed the same log collapsing at the same moment for the third time, it stops being background and becomes a distraction. A generated fire has no seam to notice, so it can sit in the corner of your screen for an entire afternoon.
Are the sound and the picture connected?
Yes, and it is the detail that sells it. Every crackle you hear also injects a burst of heat at the base of the fire, so you see the flame flare on the same pop you just heard. Most ambient apps play an audio track next to an unrelated animation; here they are one system. The crackles also arrive at random intervals rather than on a fixed timer — a fixed timer sounds like a metronome, and your ear catches it immediately.
How much do I have to configure?
One dial. Intensity runs from embers to a blaze, and it moves everything together: the height of the flame, how often it crackles, how many sparks come off it, and how much body the sound bed has. There is a volume control and a mute, and that is the whole interface. A widget for relaxing should not come with a mixing desk.
Does it keep running when I close the popover?
The sound does; the picture stops. That is deliberate and it is the same rule Focus Sounds follows: rendering an animation nobody is looking at is a waste of battery, but cutting the audio would defeat the point of having it on. If you want to watch it while you work, open it in its own window — the lit state is remembered, so it comes back burning rather than cold.
Will it slow my machine down?
It renders a small heat grid and scales it up rather than computing every pixel, and it stops rendering entirely when you are not looking at it. It is a fireplace, though — an animated canvas plus live audio synthesis is real work, so on a laptop running on battery it is not free. Put it out when you are done and it costs nothing.
Is it free?
Yes. Webstarted Toolbox is free and needs no account, and Fireplace is a free widget in its catalog — one click from inside the app installs it.
Get Webstarted Toolbox
Free to use. Download the app, then add Fireplace from the catalog in one click. macOS 12+ and Windows 10+.
One icon, many small tools
This is just one of the widgets in Webstarted Toolbox. Here are the rest: