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Show HN: Koi.rest – watch some fish and regain your balance

https://koi.rest

Hi there. My name is Paul. I’m a developer, an explorer and I’ve got ADHD. As of the beginning of August, I’m also unemployed.

This last part, along with everything else this past year, has caused me a great deal of stress.

While our balcony zen garden project is yet to be completed, I had an idea to create a virtual one that everyone can use.

It's an idea that, unfortunately, I’ve been postponing for a while now, mostly because I have no fucking idea how to do it as I don’t know JavaScript, and I don't have the capacity to learn it right now.

So I let perfect be the enemy of good and, well... just kept the idea to myself.

Then I said "fuck it" and used AI to make the thing I really wanted to make.

I realized I didn't want "perfect". I wanted "good enough".

I tweaked, added, removed, drew, researched, questioned, tested... I just wasn't the one coding it.

So now, instead of occupying my brain, it now lives on the internet for others to enjoy.

Yes, there’s something noble about making something entirely on your own, but what good is an idea that just sits in my head?

So here I am. I made the thing. The weird, little, quiet koi pond.

The silly project of passion. The little corner of the internet to let strangers watch fish quietly, together.

I hope this pond helps you as much as it helped me.

( 65 comments | 102 points | on HN )
Re:Show HN: Koi.rest – watch some fish and regain your balance by johnsmith1840 on Thursday September 24, 2026 @08:17PM (#49838568)
Been on a train of thought recently that with AI making web dev so much easier that we should be making more beautiful experiences.

I have always felt ultra minimalism is partly a way of fighting bugs. Why can't we put more effort to make every site a great experience in of itself?

Been experimenting with going way beyond my usual frontend work for something truly special. This made me think if it. It's 10x the effort but that's about the same effort I put in before manually making a minimal one.

I want more koi fish swimming around my saas.

Re:Show HN: Koi.rest – watch some fish and regain your balance by dylanhouli on Thursday September 24, 2026 @07:11PM (#49838038)
Cool idea but as some others have said the website was running quite slow for me. I noticed it at first when hovering over the 'enter' button (so before even loading the pond) because the hover animation on the button kicked in really late feeling.

Then actually entering took a few seconds and it was quite laggy looking at all the fish.

Once those things are fixed I think the idea is neat. It would be cool to be able to interact with the pond in some way (click lily pads, drop food in the water, click the water to make it splash) but that might not be what you're going for with this

Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @10:22PM (#49839495)
Thank you for the feedback!

During my work on it I’ve been testing it on both my Linux box as well as my MacBook and haven’t encountered lag. I’m not meaning to say “it works on my machine” by this, but simply that I couldn’t have caught this before.

I will definitely address the lag issue, and find a more “graceful” way for koi to enter and leave the pond.

About interactivity – I was thinking about this both during the development as well as just when I had the idea and the intention was always to not have any, simply because in my own experience we are always doing “something”, and this was a way to get a little bit of the opposite – to do nothing.

But I can see how some micro-interactions could be useful. A sort of a “popping bubblewrap” action.

Re:Show HN: Koi.rest – watch some fish and regain your balance by applfanboysbgon on Friday September 25, 2026 @02:25AM (#49840840)
> I’m not meaning to say “it works on my machine” by this, but simply that I couldn’t have caught this before.

If you knew what you were doing you could have reasoned about what your code did, though. Such is the danger of trial-by-error vibe coding. I personally closed the tab because the audio kept cutting off arbitrarily after some minutes. Not to criticise you unduly because this was a cute concept, but I hope you might take away that LLMs are not only not perfect, but are also only "good enough" if your standards for "good enough" are particularly low, and use this as motivation to learn more in the future instead of always relying on them.

I think no interaction is good for an offline pond, but I do think some tiny little bit of interaction would be nice online since it adds a touch of humanity, being able to see other people and interact with them in some small way.

Re:Show HN: Koi.rest – watch some fish and regain your balance by nullify88 on Friday September 25, 2026 @04:30AM (#49841706)
I think you are being too harsh. Even before AI, software and games would often work great on one computer and poor on other computers. I believe that isn't because they understood the programming less or their standards were low, but because there is so much variance between computer hardware, the firmware inside, and the software running on it that you can't guarantee software to run identically across many combinations.

Similarly it's not unusual for one website to behave differently across browsers.

Re:Show HN: Koi.rest – watch some fish and regain your balance by applfanboysbgon on Friday September 25, 2026 @05:28AM (#49842111)
Sure, to some extent. What I really took issue with is saying "I couldn't have caught this", which is a sort of learned helplessness. It's very often the case that, independent of inscrutable platform differences, LLMs just produce extremely shoddy code that obviously does not scale, and there is a whole class of problems you can solve before they become problems if you actually know how to program.

My intent was not to be harsh, though. I was trying to make a point that one can learn and do better. Coding is very much not solved.

Re:Show HN: Koi.rest – watch some fish and regain your balance by solarkraft on Friday September 25, 2026 @10:54AM (#49845534)
I agree that couldn’t is a tad too far, you could always have tested more. But even with more testing you could’ve missed this, completely irrespective of the use of AI.
Re:Show HN: Koi.rest – watch some fish and regain your balance by lionkor on Friday September 25, 2026 @03:30AM (#49841305)
Hi, this might not be obvious to you so I wanted to explain it:

Testing on a single device, or two devices, is not enough. I'm on a laptop with 96 GB ram and a Ryzen AI 9 HX PRO 370, and it's running at 3 FPS.

The crucial part is browser performance and network latency. You need to test across multiple browsers, but also evaluate frame times, CPU load, GPU load, etc. so you can make a reasonable estimate whether it's fast or not.

Then, when you realize that its not good enough, e.g. on firefox, you use firefox's profiler to see which parts are slow. LLMs would guess, probably, but you have to measure.

Welcome to software engineering.

Re:Show HN: Koi.rest – watch some fish and regain your balance by thoughtpeddler on Thursday September 24, 2026 @08:07PM (#49838467)
Super cool, thanks for making this! I've been there with you on the perfectionism. Glad that 'good enough' won this time, and we're all the better for it. Keep going!
Re:Show HN: Koi.rest – watch some fish and regain your balance by hatthew on Thursday September 24, 2026 @06:47PM (#49837833)
It's running at 3fps or something like that. Is that a me problem or a "lots of traffic" problem?
Re:Show HN: Koi.rest – watch some fish and regain your balance by efilife on Thursday September 24, 2026 @08:19PM (#49838575)
seems to be a "vibe-code" problem
Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @10:25PM (#49839518)
Vibe coded or not, I was honestly trying in on two desktops (and two browsers) and a mobile phone and didn’t get any lag, which is why I couldn’t have caught this before.

It might be some other combination that might contribute to whether there is or isn’t lag, and I’m going to try and find what it is :)

Re:Show HN: Koi.rest – watch some fish and regain your balance by hatthew on Friday September 25, 2026 @03:20AM (#49841222)
I was on firefox on a newish mac, but it was when there were some any fish that they fully covered the screen, couldn't see the bottom of the pond.
Re:Show HN: Koi.rest – watch some fish and regain your balance by efilife on Friday September 25, 2026 @01:51PM (#49847791)
You don't know what's causing it to run this badly because you didn't write it. You now have to reverse-engineer "your code". This is a problem of vibe-coding
Re:Show HN: Koi.rest – watch some fish and regain your balance by 40four on Thursday September 24, 2026 @09:20PM (#49839074)
I haven’t tried it on desktop, but it’s running silky smooth for me on iPhone. No lag at all. I see some others complaining of that too so not sure what the issue is.
Re:Show HN: Koi.rest – watch some fish and regain your balance by JKCalhoun on Thursday September 24, 2026 @11:12PM (#49839794)
See if there's anything in the Web Inspector console (or equivalent). Maybe an error or assertion is firing off.
Re:Show HN: Koi.rest – watch some fish and regain your balance by pozol on Thursday September 24, 2026 @06:42PM (#49837765)
This is great! The sounds and visuals are a great way to recenter. Only UX thing I’d say, is it would be nice, and less distracting, if other “users/koi” popping in instead kind of faded in. Them suddenly appearing kind of pulls you out of the zen mode. Awesome idea!
Re:Show HN: Koi.rest – watch some fish and regain your balance by jeromechoo on Thursday September 24, 2026 @06:01PM (#49837291)
This is neat. I like the zen background sounds. I'm particularly fascinated by digital third places with extremely limited social interaction (like cursor camp by Neal). I think it has something to do with the impossibility of something like this happening in real life.

That said, I'm not sure how real the "koi you see are other people visiting the pond together with you" bit is. I only ever saw 3 swimming koi. Maybe that's the base.

Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @06:22PM (#49837544)
Hey! That’s the base, correct. Three are always there so if someone joins and nobody else is using it – they’re never alone.

In essence, when you someone joins the counter goes up and another koi will spawn locally.

It’s a bit nerfed from my initial idea to sync the movement of each koi, but I might do that in the future.

It looks like the way I deployed (Railway) it causes `429 Too Many Requests` to be returned, so I’ll definitely have to look into that. But it’s 1:21 AM so tomorrow.

Thank you for letting me know!

Re:Show HN: Koi.rest – watch some fish and regain your balance by p1necone on Thursday September 24, 2026 @06:50PM (#49837858)
I noticed the koi pop in and out of existence on visible parts of the screen - it would be nice if incoming koi swam into frame from offscreen, and outgoing koi swam offscreen before disappearing.
Re:Show HN: Koi.rest – watch some fish and regain your balance by dolebirchwood on Thursday September 24, 2026 @07:30PM (#49838195)
Yes, that was very jarring. I didn't bother reading the intro text that said the other fish are other people on the site, so I just thought this was janky crap. The creator shouldn't assume people read anything. I see a button that says "Enter", I click - I'm not reading anything else. So it's going to cause a lot of confusion when I arrive in a pond filled with way too many fish for a zen-like experience, and even more annoyance at the constant flickering in and out.
Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @10:29PM (#49839537)
Thank you for the feedback! It’s definitely on my project task list.

So far the options I thought of were to fade or scale the koi as they enter or leave the pond. I will try to see what will work visually here.

Re:Show HN: Koi.rest – watch some fish and regain your balance by applfanboysbgon on Thursday September 24, 2026 @06:20PM (#49837524)
It appeared to be real earlier, or at least simulated being real. I watched for 10 minutes and there were ~10 koi in my pool, with koi routinely flickering in and out of existence as though they suddenly joined or left. That said, I see three static koi now. Entirely conceivably that HN killed the backend and triggered a failsafe.
Re:Show HN: Koi.rest – watch some fish and regain your balance by keithnz on Thursday September 24, 2026 @06:46PM (#49837814)
lots and lots of koi at the moment!
Re:Show HN: Koi.rest – watch some fish and regain your balance by Cider9986 on Thursday September 24, 2026 @06:13PM (#49837446)
I really like the UI especially the about page. I don't think you are supposed to be able to see the about page on the playing page (it took a bit to start and then started when I was in about) but it looks good there with the blur.

Here's a list of other sound/relaxation websites: https://fmhy.net/audio#ambient-relaxation.

This one is pretty funny but not relaxing to me. It may be a covid remnant: https://imisstheoffice.eu/

Re:Show HN: Koi.rest – watch some fish and regain your balance by Coeur on Thursday September 24, 2026 @07:58PM (#49838399)
Have a big virtual hug from me, hxii!
Re:Show HN: Koi.rest – watch some fish and regain your balance by natnatenathan on Thursday September 24, 2026 @07:23PM (#49838148)
I understand your trepidation sharing this, given how often 'vibe coded' is used derogatorily. I like what you made, thank you.
Re:Show HN: Koi.rest – watch some fish and regain your balance by marcuskaz on Thursday September 24, 2026 @06:52PM (#49837875)
Too many koi fish is stressful (and slow)

I'd love a version without the multiplayer and just zen

Re:Show HN: Koi.rest – watch some fish and regain your balance by mcint on Thursday September 24, 2026 @06:56PM (#49837915)
Looks like it locks the number when you first load. I had it open for 30 minutes, with just 3 fish, but after reading your comment, re-opened to find 3 dozen.

Choice about busyness would be nice.

Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @10:34PM (#49839570)
Thank you for the feedback! Will definitely add that as an option.
Re:Show HN: Koi.rest – watch some fish and regain your balance by Suhinnall27 on Thursday September 24, 2026 @07:35PM (#49838237)
This is honestly super cool, and a lot of fun. I was about to say something about the koi fish spawning and despawning until I read that they are the other users on the site, which is an awesome mechanic. Is there a way to set this as a screen saver or background?
Re:Show HN: Koi.rest – watch some fish and regain your balance by farrysaini on Thursday September 24, 2026 @07:38PM (#49838265)
This is great! I would really like this as live background on Android.
Re:Show HN: Koi.rest – watch some fish and regain your balance by wateralien on Thursday September 24, 2026 @06:45PM (#49837808)
I do this with the screensavers on the Apple TV device. They’re amazing.
Re:Show HN: Koi.rest – watch some fish and regain your balance by grvdrm on Thursday September 24, 2026 @06:50PM (#49837863)
Awesome. Top of bookmark list for a daily zen!
Re:Show HN: Koi.rest – watch some fish and regain your balance by Jtarii on Thursday September 24, 2026 @06:56PM (#49837916)
You might want to prompt ChatGPT to increase the frame rate of the fish animation.
Re:Show HN: Koi.rest – watch some fish and regain your balance by ecto on Thursday September 24, 2026 @07:00PM (#49837950)
You might want to prompt for some manners, and why humans have them.
Re:Show HN: Koi.rest – watch some fish and regain your balance by emkoemko on Thursday September 24, 2026 @07:34PM (#49838224)
weird comment.... this was vibe coded so yes it has terrible performance why wouldn't we want more fps?
Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Thursday September 24, 2026 @10:34PM (#49839563)
Vibe coded doesn’t necessitate bad performance. As I’ve replied to others – during testing I didn’t get any lag across three different devices that I own, so I just didn’t have a chance to catch this before.

That’s not to say “it’s a you problem”, but rather that I currently don’t know under which circumstances the lag appears.

Re:Show HN: Koi.rest – watch some fish and regain your balance by wartywhoa23 on Friday September 25, 2026 @04:29AM (#49841702)
Yeah, by pointing out flaws in slopware, one doesn't only show oneself as a boor, but also as a terrorist and foreign agent why tries to bury down the hopes of the humankind, err, it's 0.001% I mean.
Re:Show HN: Koi.rest – watch some fish and regain your balance by Jtarii on Friday September 25, 2026 @06:08AM (#49842406)
It's also bad manners to post slop.
Re:Show HN: Koi.rest – watch some fish and regain your balance by _qua on Thursday September 24, 2026 @06:57PM (#49837928)
Love it
Re:Show HN: Koi.rest – watch some fish and regain your balance by suzukivenom on Thursday September 24, 2026 @06:44PM (#49837791)
thanks! had a really rough day
Re:Show HN: Koi.rest – watch some fish and regain your balance by bredren on Thursday September 24, 2026 @07:38PM (#49838258)
Great post, OP. Way to overcome. Keep it up.
Re:Show HN: Koi.rest – watch some fish and regain your balance by samrj12 on Thursday September 24, 2026 @09:32PM (#49839173)
Seems like quite laggy (I suppose bcz of heavy assets and rendering). I would have liked it more if we had some interactive elments with the pond or the fishes because I can only stare at it for some seconds lol
Re:Show HN: Koi.rest – watch some fish and regain your balance by max979 on Thursday September 24, 2026 @10:11PM (#49839439)
Had a desktop aquarium once, very calming. This digital version is probably less messy and just as effective.
Re:Show HN: Koi.rest – watch some fish and regain your balance by kalms on Friday September 25, 2026 @12:53AM (#49840323)
If small size, I recommend lots of plants and capping any "live" substrate with sand. Had one going with shrimps and a few endlers for years. I only topped the water up and very occasionally changed the water. Not that it really needed it.

After the first few weeks, it just soldiered on with minimal algae or intervention needed. It's a lovely thing to have, I can recommend it. (That said, I also have a small aquarium problem according to the wifey)

Re:Show HN: Koi.rest – watch some fish and regain your balance by rhplus on Thursday September 24, 2026 @10:33PM (#49839559)
Pleasant flashbacks to the Windows 95 classic Serene Screen “Marine Aquarium”

https://youtu.be/PprsZgA-kxs?si=waSpdI4J323fNNGh

https://www.pcgamer.com/gaming-industry/a-former-air-force-p...

Re:Show HN: Koi.rest – watch some fish and regain your balance by JKCalhoun on Thursday September 24, 2026 @11:15PM (#49839805)
Exactly how I have found vibe-coding to be. I make things with LLMs help that I otherwise wouldn't be bothered to. I've vibe-coded perhaps a half dozen tools for my personal use and am happier for it.

Keep going.

Re:Show HN: Koi.rest – watch some fish and regain your balance by DiabloD3 on Friday September 25, 2026 @01:21AM (#49840452)
You didn't make anything at all, though.

Also, please talk to a lawyer before slapping a Copyright on anything you didn't make. Machine-made products cannot be Copyrighted in the US and most Berne Convention countries, and you cannot own the output of an LLM, nor can you legally shield yourself from the consequences.

Re:Show HN: Koi.rest – watch some fish and regain your balance by fxwin on Friday September 25, 2026 @03:57AM (#49841491)
I think "tools for personal use" implies both that their utility is more important than craftsmanship, and that they aren't public.
Re:Show HN: Koi.rest – watch some fish and regain your balance by JKCalhoun on Friday September 25, 2026 @06:31AM (#49842586)
I guess I don't get caught up in the distinction of whether I created the software or not. But for Claude/Gemini and me, it would not have existed—and did not exist beforehand.

At the end of the day, I have tools that are helping with screen-printing (and stereo photography, and other hobbies). I don't care if Brownies gathered around my computer when I was sleeping and wrote the software (to my specification).

I suppose that puts me in that group of programmers that are focused on the end-product, agnostic as to how the thing was made. I have truly never enjoyed the plumbing part of the job—just want clean tap water.

(Well, the algorithms have always fascinated with a mathematical appreciation: matrix transforms, Bloom filters, etc. Aspects like robustly handling multi-threading has always been a kind of painful Sudoku puzzle I try to do in my head—while a challenge, I sometimes would rather not hurt my brain that way. The tedium of stubbing in functions, filling them in to make a boiler-plate image cache–never very interesting.)

I don't copyright anything I do. I had some software published 36 years ago and the publisher slapped a copyright on it, but I have never done so.

Re:Show HN: Koi.rest – watch some fish and regain your balance by fxwin on Friday September 25, 2026 @06:42AM (#49842662)
> I suppose that puts me in that group of programmers that are focused on the end-product, agnostic as to how the thing was made. I have truly never enjoyed the plumbing part of the job—just want clean tap water.

FWIW I think most people don't belong to either group exclusively. I often care mostly about the outcome (e.g. at work or when i make small tools for myself), but occasionally i care mostly about the process (e.g. when learning a new programming language or solving problems akin to advent of code)

Re:Show HN: Koi.rest – watch some fish and regain your balance by JKCalhoun on Friday September 25, 2026 @07:52AM (#49843319)
Yeah, I enjoy some of the puzzles that come along. And the learning part you mentioned—that has been fun.

I think you're right that it's more of a spectrum.

Re:Show HN: Koi.rest – watch some fish and regain your balance by spectre3d on Saturday September 26, 2026 @10:16PM (#49862704)
He made something more important and influential than most of us ever will, so it’s interesting to hear his thoughts on these things.

Where did you get the idea that anyone was talking about trying to copyright vibe-coded tools for personal use?

Re:Show HN: Koi.rest – watch some fish and regain your balance by lappet on Friday September 25, 2026 @12:48AM (#49840296)
This is really cool! So peaceful.
Re:Show HN: Koi.rest – watch some fish and regain your balance by skibz on Friday September 25, 2026 @03:22AM (#49841240)
I dig the voronoi used as an approximation of caustics!
Re:Show HN: Koi.rest – watch some fish and regain your balance by henrydoughty on Friday September 25, 2026 @04:07AM (#49841570)
sat on this a bit. needed it actually. thanks for putting it up instead of leaving it in your head
Re:Show HN: Koi.rest – watch some fish and regain your balance by Paradigm2020 on Friday September 25, 2026 @04:56AM (#49841899)
A fellow ADHD sufferer.

I first clicked the enter button and, for once thanks to, slow loading I saw the 15 30 etc options...

So went back and clicked 15 and waited and waited not realizing I needed to press enter. So I'd change that to 15 / 20 / 30 / timeless options and no enter option...

Also after being in the experience for a few second probably I was wondering if the timer was actually running... So maybe show the timer for a few seconds (1500, 1459, 1458,1457 fade...)

Also there was no sound when I entered and then when I clicked the button I got the same text as the hackernews description and it was slightly off and unexpected (slightly off probably being a Firefox + android combo) but yeah would appreciate 2 buttons one settings, one information about or alternatively only show it once and afterwards just the panel).

Also tried to install it as an app as I'd love to have it full screen but kept the bar...

Overall it's brilliant and I'm grateful that you went the ai route and launched.

If you wanted to turn it into a paid project you could go the pixel route and offer this version for free and then the option for a one off payment to add different background, fish representations etc... He made enough money to buy a Mac to make a version for iOS as well and seemingly makes a living off it (oc in argentina, probably not possible in a HCOL lpcation.

Anyway thank you so much and hope there is some useful info here.

Have a great day

Re:Show HN: Koi.rest – watch some fish and regain your balance by lakeffect on Friday September 25, 2026 @07:34AM (#49843129)
Running well for me! Would also love some very minimal interaction ability. Making water ripple, etc. Something to ease me into the idea of taking a deep breath and sitting while watching the koi.
Re:Show HN: Koi.rest – watch some fish and regain your balance by rickydroll on Friday September 25, 2026 @09:29AM (#49844366)
Like others, I'm getting the one-frame every 2 or 3 seconds behavior. But I'm finding something I didn't expect. I'm listening to the sound and not watching the koi, and that is incredibly soothing/relaxing for my ADHD mind. If you generate the audio locally, maybe that should be a single page all by itself and not worry about the fish, or perhaps I should say, And thanks for the fish.
Re:Show HN: Koi.rest – watch some fish and regain your balance by bosunknows on Friday September 25, 2026 @10:14AM (#49844992)
This immediately made me think of the old iOS app Koi Pond. In 2008, it was incredible. I remember being amazed by the water that you could spash/swirl.

https://www.macrumors.com/2008/08/20/the-1-paid-app-koi-pond...

Re:Show HN: Koi.rest – watch some fish and regain your balance by safaelmali on Sunday September 27, 2026 @07:16AM (#49865646)
How are the ambient sounds made-looped recordings or synthesized in the browser? I’m curious how you handle repetition during longer sessions.
Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Sunday September 27, 2026 @08:50AM (#49866239)
The audio was sourced from pixabay, and is not looped.

The start and end points have gain faded in a curve, to avoid any clicking especially since the audio samples are not seamless.

Previously a second buffer was used for crossfading, but it doubles the memory consumption with very little benefit.

I was toying with the idea of synthesizing audio from smaller samples directly, but that's an idea for the future :)

Re:Show HN: Koi.rest – watch some fish and regain your balance by safaelmali on Sunday September 27, 2026 @09:06AM (#49866368)
Thanks for explaining! The memory tradeoff is interesting. Do the fades create a noticeable dip between samples, or do the other ambient sounds mask it?
Re:Show HN: Koi.rest – watch some fish and regain your balance by hxii on Sunday September 27, 2026 @10:25AM (#49866907)
The curve on both ends is very brief (20ms, so 40ms total) and is more to deal with any abrupt clicking.