There is no problem with YAML, just like there was no problem with XML at all. The problem is with the software devs who use it for the wrong thing. I just wonder why JSON doesn't get all the hate, while it is a terrible format also: it is not streamable (YAML is), it doesn't have comments... and non-standard workarounds are used for these features. Norway better than YAML, in my opinion.
I also wonder why it’s the 2012 version of the language who gets all the hate, instead of the hate being directed at Google, who doesn’t care about putting resources towards updating the main offender, Kubernetes’ YAML 1.1 parser. https://github.com/kubernetes/kubernetes/issues/34146#issuec...
Would totally love to do that bro, is not a resource or finance problem- not even talent - AI could probably do it with oversight .. but No Promo.. cant touch it once another guy declared it complete.. that s them rules.
There numerous problems with YAML. It is underdefined, ambiguous, fragile, and is just impossible to write a portable parser for.
JSON is naive, lacks almost everything. But is supereasy to parse and read.
As funny as it sounds, XML is overspecified. Parsing is possible and predictable but supporting the full standard (all of them) is so much work that nobody does it anyway.
So, given the choice above, i'd go for naive simplicity.
There are plenty of problems with YAML as the article shows. The biggest problem with YAML is, that serializer and deserializer need to agree on rules outside of the spec, because otherwise they can be both compliant and still don't understand each other.
I find json annoying to write a lot of the time, but I do enjoy that it's a lot more difficult to get wrong than yaml. The json spec is pretty clear, and can be learned and memorized by any programmer in 5 minutes. I'd much rather write in a format that's slightly annoying than a format that's slightly ambiguous.
> YAML is (or at least, is declared by its maintainers to be) a superset of JSON, making any JSON document also a valid YAML document.
> So surely if YAML is streamable, JSON must be too?
Given YAML is not a subset, but a superset of JSON, as you correctly noted, I'm not sure how you reached that conclusion.
Offtopic note: I wanted to dig the wiki superset link up the lazy way, so searched for superset, and all I got was endless list of marketing trash links. Even on DDG. RIP, we are on the Dead Internet.
I wrote a C++ library at work that, among other things, serializes/deserializes to JSON, CBOR and BSON. I don't get that point.
The first two formats I've implemented as fully streaming, the serializers emit into an output iterator one character/byte at a time and the deserializers only need to hold one value at a time (mostly for strings, and not even for CBOR's byte arrays, which are streamed). BSON requires full document instantiation because of byte offsets and is genuinely anti-streaming in its design.
I happen to have implemented a serializer for YAML, fully streaming, mostly as a compact-ish human-readable debug data representation. I can scarcely think of fates worse than having to write a spec-compliant YAML parser.
Surprised TOML didn't get mentioned in the alternatives section, it's probably my favourite configuration format.
I'm working on a project now that uses YAML for configuration (it makes more sense in this context than TOML) and am parsing it using Rust's `serde` crate (via `serde_norway`). It's not so bad if you use `#[serde(deny_unknown_fields)]` everywhere.
My usage of YAML has been limited. For the times I have used it (kubenetes, docker compose, other things, etc) -- I don't get what it so special about it.
It just seems reinventing the wheel again and again.
I am not suggesting JSON is perfect, either. However I do prefer it to YAML (and XML) by a mile.
It's a shame s-expressions never taken off.
(select (id name)
(:from users)
(:where (= name "Peter")))
I think KYAML[1] is very relevant here. KYAML is a strict subset of yaml[2], supported natively by kubernetes tooling in most recent versions.
In my opinion it's closer to JSON with comments than to YAML, but overall it looks like a pretty nice format, that solves some of pain points of both technologies. This is not the first nor the only JSON-with-comments format, so I wonder if it manages to break out of kubernetes world and become popular.
You really should not blame it on YAML that if you put a random hash value in a field that it may be a number. Like, duh. If you want a string, use quotes.
It’s because ppl are not using it correctly, it was designed for configs and now it’s being used as a programming language… a language without types and debugger. It’s frustrating devs because they find the issue at the deployment time, not the compile time.
Personally I did never pick the YAML as a first format for the configs, only my ruby friends did that.
- "something broke" is way better than stack traces with line numbers
That sums it up. Its the same since the days of XML. Someone decides to make something configurable externally and then everything gets put in there for convenience. Now we are programming in XML/YAML without even a stack trace (or a debugger, or call hierarchy, or type checking or ... )
Next time the author would like to write an article like that, it’s better that they offer a new standard that is as flexible while also doing the work YAML is doing today
That’s the problem people IMO don’t understand - flexibility is one of many requirements; simplicity and ecosystem around are two more.
Hating YAML is same as being childish - yo using like something but can’t come up with anything better. Worse than YAML can be only complaining about YAML. Hating YAML is a cliche.
Its much easier to come up with jokes like this website than to change the ecosystem for better.
And I definitely think the websites like this is opposite to the engineering approach.
> That’s the problem people IMO don’t understand - flexibility is one of many requirements; simplicity and ecosystem around are two more.
Biggest issue IMO is moving goal posts and people wanting one format to do it all. Different formats are good for different things, except YAML, which again tries to do it all yet excels at nothing.
Am I the only one who finds this writing style hard to read?
I stumbled upon this page a few years back and was very confused by the language. It took me some time to parse it and realize that all the comments are actually sarcastic. Overall, the general style feels like I'm reading comments on TikTok.
It's not that I'm against this style; it's just that you don't expect it in a technical article.
Google put forward KYAML recently (https://www.kubernetes.dev/resources/keps/5295/), it looks like a more sane way forward.
JSON is naive, lacks almost everything. But is supereasy to parse and read.
As funny as it sounds, XML is overspecified. Parsing is possible and predictable but supporting the full standard (all of them) is so much work that nobody does it anyway.
So, given the choice above, i'd go for naive simplicity.
And then you have whatever the hell OpenAPI uses.
Either you have an infinite spec, or you always have things outside it.
[0] YAML would allows you to tag the type, but nobody does it anyway
So surely if YAML is streamable, JSON must be too?
Or are the YAML maintainers incorrect?
Given YAML is not a subset, but a superset of JSON, as you correctly noted, I'm not sure how you reached that conclusion.
> Or are the YAML maintainers incorrect?
I think you should check this page before making snarky comments: https://en.wikipedia.org/wiki/Superset
See also the comment below: https://news.ycombinator.com/item?id=49476489
Offtopic note: I wanted to dig the wiki superset link up the lazy way, so searched for superset, and all I got was endless list of marketing trash links. Even on DDG. RIP, we are on the Dead Internet.
See Examples section.
Given: - YAML support streaming - any JSON is valid YAML
Conclusion - any JSON is streaming
The first two formats I've implemented as fully streaming, the serializers emit into an output iterator one character/byte at a time and the deserializers only need to hold one value at a time (mostly for strings, and not even for CBOR's byte arrays, which are streamed). BSON requires full document instantiation because of byte offsets and is genuinely anti-streaming in its design.
I happen to have implemented a serializer for YAML, fully streaming, mostly as a compact-ish human-readable debug data representation. I can scarcely think of fates worse than having to write a spec-compliant YAML parser.
The json spec just doesnt do anything like that but jsonl does.
I agree that Norway is better than YAML. Let's keep Norway and dump YAML.
> There is no problem with YAML
I am reminded of: "There are no American infidels in Baghdad. Never!"
Well most of that is due to 1.1 which has been deprecated god knows for how long.
1.2 does not have the 'Norway' problem any more.
Tooting my own horn, this is how a modern YAML library looks like nowadays:
https://github.com/pantoniou/libfyaml
I'm working on a project now that uses YAML for configuration (it makes more sense in this context than TOML) and am parsing it using Rust's `serde` crate (via `serde_norway`). It's not so bad if you use `#[serde(deny_unknown_fields)]` everywhere.
It just seems reinventing the wheel again and again.
I am not suggesting JSON is perfect, either. However I do prefer it to YAML (and XML) by a mile.
It's a shame s-expressions never taken off.
Or I know - its a sample, but you get it. :-)I think KYAML[1] is very relevant here. KYAML is a strict subset of yaml[2], supported natively by kubernetes tooling in most recent versions.
In my opinion it's closer to JSON with comments than to YAML, but overall it looks like a pretty nice format, that solves some of pain points of both technologies. This is not the first nor the only JSON-with-comments format, so I wonder if it manages to break out of kubernetes world and become popular.
[1] https://kubernetes.io/blog/2026/08/11/how-to-pretty-print-ku...
[2] https://www.kubernetes.dev/resources/keps/5295/
Unlike hjson, toml and many others, JSON5 didn't try to reinvent the wheel and create a totally new syntax.
Instead, they took 2 already well established standards (JSON and ECMAScript 5.1) and put them together.
I think that it is pleasant enough to write by hand while not creating yet another new syntax that you have to get used to.
[0] https://json5.org/
You really should not blame it on YAML that if you put a random hash value in a field that it may be a number. Like, duh. If you want a string, use quotes.
You mean other than when we won't be? :-(
Personally I did never pick the YAML as a first format for the configs, only my ruby friends did that.
That sums it up. Its the same since the days of XML. Someone decides to make something configurable externally and then everything gets put in there for convenience. Now we are programming in XML/YAML without even a stack trace (or a debugger, or call hierarchy, or type checking or ... )
I won't even look at it, and it will be just fine.
Hating YAML is same as being childish - yo using like something but can’t come up with anything better. Worse than YAML can be only complaining about YAML. Hating YAML is a cliche.
Its much easier to come up with jokes like this website than to change the ecosystem for better.
And I definitely think the websites like this is opposite to the engineering approach.
Not defending YAML though in particular.
Edit: grammar
Biggest issue IMO is moving goal posts and people wanting one format to do it all. Different formats are good for different things, except YAML, which again tries to do it all yet excels at nothing.
I stumbled upon this page a few years back and was very confused by the language. It took me some time to parse it and realize that all the comments are actually sarcastic. Overall, the general style feels like I'm reading comments on TikTok.
It's not that I'm against this style; it's just that you don't expect it in a technical article.
Nobody anywhere needed more INI files.
Care to elaborate? We are using TOML for config files and just do fine.