Identifying the technologies behind a web site involves a lot more than looking at Apache's mod_php headers (which you can and should turn off for security reasons). The tools for figuring out what runs a site actually do a really good job by looking for multiple identifying features. Marketers and SEO people use tools like BuiltWith and Wappalyzer (and many others, most of them not free). You may not know about those tools or how well they work, but a quick browse of that space will disabuse you of the idea that these surveys just crawl looking at server headers.
Multiple independent surveys of web back-end technologies by different outlets, across many years, have reached the same conclusion: PHP powers approximately 3/4ths of public web sites/applications. I do a lot of PHP work and I see PHP used heavily in restricted/private web applications as well -- internal sites that won't show in these kinds of surveys. One school I work for has one public WordPress-powered site and several internal-only WordPress sites, and multiple internal PHP-powered sites not based on WordPress, including Moodle (learning management system) and their student management system.
The large ecosystem, relatively large population of experienced developers, and ease of deployment play into the decision process. Sometimes it comes down to hosting costs or other non-technical factors.
Deducing the number of jobs for PHP developers based on job ads will mislead you. Most jobs get filled internally, informally, or by recruiters before they get posted online (because that costs). If you don't see a lot of ads for PHP developers that might mean few jobs exists (which wouldn't match the experience of anyone who works with PHP). It may also mean the jobs got filled before the employer has to pay to advertise the job. A position for a 5+ yrs experience Elixir dev may sit open for months, but I can and have filled PHP dev openings in a few days, from a large list of applicants acquired by a free posting in a local PHP user's group forum, without having to post in public job forums or do LinkedIn email blasts.
We should also consider that web developers with more than a few years of experience have likely worked with multiple tech stacks, and those of us with 10+ years very likely cut our teeth on PHP. I started in the '90s with ASP and ColdFusion, with some Perl, and then saw employers move to PHP (and a few to Rails a few years later) mainly because ASP (which predates .NET) and ColdFusion required increasingly expensive licenses whereas PHP did not. Among experienced web developers you will find many/most of them have worked with PHP, and could work with it again, though they may prefer something else. Likewise I know COBOL and could fall back on that if more interesting work dried up for me, but I don't call myself a COBOL developer or look for jobs in that space.
Thank you for your comment. I was definitely wrong about the different methods used.
This is why I love Hacker News. Always nice to learn something.
I still think the stats they provide are a bit weird since there is no "unknown" category. If they can't find the backend technology used for 5% of websites, it changes the whole result, and from what I have seen they don't provide this information.
But your really nice and detailed answer tells me I might be wrong once more.
I don’t see an “unknown” category. A large number of unknowns could skew the results if we had reason to believe those mostly represent non-PHP sites. Do we have any reason to think those unknown sites show a different distribution than the known sites? Do enough unknown sites exist to meaningfully affect the results?
Using your 5% example, supposing that 5% unknown includes no PHP sites, that only brings the PHP percentage down a little. It doesn’t change the main point that PHP dominates by a wide margin.
Some technologies seem to give more tells than others. Which means some technologies could be way more invisible than others. I am not sure we can suppose the known and unknown technologies have the same ratio.
I quickly checked some websites with BuiltWith and Wappalyzer and from my personal totally unscientific and small sample data, they seem to detect more easily PHP than other languages like Python.
Again, I don't know. But I took 5% to be optimistic. It could be 30% or 50%. And then the whole picture changes.
Edit: Funny thing, it even adds PHP to some sites I know (almost for sure) don't use PHP. Like GitHub using Ruby (true) and PHP with Drupal (???).
PHP probably gets used in low-price shared hosting setups or managed hosting more than other languages, where those tells will show up because the developer can't change the Apache or PHP configuration files. And of course the big PHP numbers come from WordPress, which has its own tells. Developers don't necessarily choose WordPress -- the customer chooses it or starts with it and that's what developers have to work with.
More interesting to me than the actual breakdown by language is the reaction from developers when this article or something like it gets published. I look at PHP and every other language I've had to learn and use in my career (a lot of them, I started 40 years ago) as tools to get a job done. I don't get personally invested in languages or tools. I don't identify as a "PHP developer" or "Go developer" or "Javascript developer." I write code and manage systems to make money. What language or tools I decide to use (or more often have to use because someone got to decide already) makes little difference. PHP got popular because it was free (as opposed to ASP and ColdFusion, which were not) and was less inscrutable than Perl. As a long-time C programmer with experience on ASP, ColdFusion, and Perl I had no trouble learning PHP. I likewise had no trouble learning Ruby and Rails, Python, Javascript, and Go. All of those will eventually fade into the world of legacy tools, along with everything else I've learned and used. I don't care, I don't have any part of my personality or ego invested in them. I don't get how other developers get so invested, call themselves "Rust programmers" or whatever and then get hostile and defensive. I guess that's human nature -- I see Tesla owners identifying with their car brand, and I remember the cult around the Saturn cars. I interpret a lot of the apparent insecurity and hostility as inexperience, but it seems to go beyond that into a kind of programmer identity politics.
If PHP dominates public web sites, so what? That has no effect on what tools I choose to learn or use, or how I value my skills, or much of anything that I might care about. I read all the time about how many people use Python, how many jobs are out there for Python programmers, and that makes no difference to me. If I get a client using Python all I care about is solving their business problems and getting paid for my expertise, not what language I have to use.
I agree. I don't think this way either. And I wouldn't be bothered with someone telling me X or Y has the main marketshare on the web.
I just don't like when figures are thrown at me and the methodology is questionable. Would be the case for any topic.
> I don't get how other developers get so invested
That's because your investment is means-to-an-end. For others, such as DHH for example, their chosen language is a means of expression and consequently they have a very strong personal investment. The Ruby and Clojure communities, for example, largely consist of developers who have a very strong personal attachment to the language and that's understandable since these languages are much more expressive whereas a language like Java will tend to attract developers who see it merely as a tool and maybe use it because it is a market leader. Languages like Ruby and Clojure demand a broadening of the mind so tend to attract users who are looking for more in a language than the standard fare of Algol-based features.
Multiple independent surveys of web back-end technologies by different outlets, across many years, have reached the same conclusion: PHP powers approximately 3/4ths of public web sites/applications. I do a lot of PHP work and I see PHP used heavily in restricted/private web applications as well -- internal sites that won't show in these kinds of surveys. One school I work for has one public WordPress-powered site and several internal-only WordPress sites, and multiple internal PHP-powered sites not based on WordPress, including Moodle (learning management system) and their student management system.
The large ecosystem, relatively large population of experienced developers, and ease of deployment play into the decision process. Sometimes it comes down to hosting costs or other non-technical factors.
Deducing the number of jobs for PHP developers based on job ads will mislead you. Most jobs get filled internally, informally, or by recruiters before they get posted online (because that costs). If you don't see a lot of ads for PHP developers that might mean few jobs exists (which wouldn't match the experience of anyone who works with PHP). It may also mean the jobs got filled before the employer has to pay to advertise the job. A position for a 5+ yrs experience Elixir dev may sit open for months, but I can and have filled PHP dev openings in a few days, from a large list of applicants acquired by a free posting in a local PHP user's group forum, without having to post in public job forums or do LinkedIn email blasts.
We should also consider that web developers with more than a few years of experience have likely worked with multiple tech stacks, and those of us with 10+ years very likely cut our teeth on PHP. I started in the '90s with ASP and ColdFusion, with some Perl, and then saw employers move to PHP (and a few to Rails a few years later) mainly because ASP (which predates .NET) and ColdFusion required increasingly expensive licenses whereas PHP did not. Among experienced web developers you will find many/most of them have worked with PHP, and could work with it again, though they may prefer something else. Likewise I know COBOL and could fall back on that if more interesting work dried up for me, but I don't call myself a COBOL developer or look for jobs in that space.