HTTP, Secure HTTP, SSL, and TLS - what they are, how they work, and why your browser keeps showing that little padlock

Written by Massa Medi| December 4, 2025

Hello, everyone. In this piece, I am going to talk about HTTP, secure HTTP, and SSL. We are going to take what you see in the browser every day and break it down in a way that makes sense, step by step, without skipping anything or glossing over the parts that actually keep your data safe.

Now, HTTP stands for Hypertext Transfer Protocol. This is probably the most widely used protocol in the world today. HTTP is the protocol that is used for viewing web pages on the Internet. So when you type in a web address like google.com, you will notice that HTTP is automatically added at the beginning of the web address. That prefix is not a decoration. It is the protocol indicator, and it tells the browser and the server how they should talk to each other.

In a moment, we are going to look at how standard HTTP works, why it sends data in clear text, what that means when your information travels across the public Internet, and how hackers can try to listen in. Then we will move into Secure HTTP - the version with the S - and see how encryption changes everything. We will also walk through SSL and TLS, how a certificate proves a site is trustworthy, what your browser checks automatically, and why so many websites now use Secure HTTP by default. Stick with me, and by the end you will know exactly what that padlock in your address bar is doing for you.

What HTTP Really Is - The Hypertext Transfer Protocol You Use All Day

Now, HTTP stands for Hypertext Transfer Protocol. When we say protocol, we are talking about a set of rules for how two computers should talk to each other. In this case, it is your web browser on one side and a web server on the other. HTTP defines how to request a page, how to include headers with extra info, how to send back a response, and how to include the content of the web page itself.

HTTP is used for viewing web pages on the Internet. So when you type in a web address like google.com, you will notice that HTTP is automatically added at the beginning of the web address. If you do not see it, the browser is often hiding it to keep the address bar clean, but it is still there as the scheme. That scheme says which rules to follow. For plain HTTP, the default port is 80, and the browser and server use TCP so the data arrives in order and can be reassembled exactly as sent.

There are a few moving parts under the hood. The browser sends an HTTP request like GET or POST. GET is used to retrieve content. POST is used to submit data like a form. The server replies with an HTTP response that includes a status code like 200 for success or 404 for not found. Alongside the content, both sides exchange headers that include things like cookies, cache instructions, and the type of content coming back. All of that is normal everyday web traffic.

And because HTTP has been around for a long time, it is everywhere. It is simple, it is light, and it gets out of the way so you can load pages quickly. But there is a tradeoff that becomes a big deal the moment you start typing anything personal into a webpage.

Standard HTTP Sends Data In Clear Text - Here Is Why That Matters

Now, in standard HTTP, all the information is sent in clear text. That means it is human readable if you see it in transit. There is no scrambling, no encryption, and no secret key that is needed to view it. So all the information that is exchanged between your computer and that web server, which includes any text that you type on that website, is transferred over the public Internet exactly as it is.

When we say public Internet, picture the path your data takes. It leaves your device, goes to your router, then to your Internet provider, jumps through a series of routers owned by different providers, may pass through exchange points shared by big networks, and only then reaches the server. If you are on public Wi-Fi at a coffee shop, your packets are traveling through an access point anyone can see. If you are on a shared office network, there can be monitoring at the firewall or proxy. In all of those places, plain HTTP looks like open text flying by.

Because it is transferred in clear text, it is vulnerable to anybody who wants it, such as hackers. A hacker does not need to be a movie-style genius with a blinking terminal. They can sit on the same Wi-Fi, use a packet sniffer, and see what is sent. Tools like Wireshark make it possible to capture packets and reassemble HTTP sessions in a few clicks. If the traffic is plain HTTP, the tool shows the exact text you typed, the URLs you visited, the cookies that were set, and more.

Now, normally, this would not be a big deal if you were just browsing regular websites and no sensitive data such as passwords or credit card information are being used. If you read a public article or view a static page with no login, there might be less to steal in that moment. But that is a narrow window. Even simple pages can include tracking cookies, search terms, or forms that leak personal info. And once you log in or enter a form, the risk becomes obvious.

But if you were to type in personal sensitive data like your name, address, phone number, passwords, or credit card information, that sensitive data goes from your computer and then it has to travel across the public Internet to get to that web server. If it is not protected, it is like mailing a postcard with your full details written on it. Anyone handling the postcard on the way can read it without opening anything.

Picture The Eavesdropper - What A Hacker Sees On Plain HTTP

So, as you can see, this hacker is stealing personal information as it is traveling over the Internet. If we were looking at the same screen I would use in a class, you would see a split view. On the left, there is a scrolling list of captured packets with lines like "GET /login HTTP/1.1" and "POST /checkout HTTP/1.1". On the right, there is a pane that reconstructs the data. It shows fields like "username=jane@example.com" and "password=p@ssw0rd" in plain text. You can also see "name=John Smith", "phone=555-123-4567", "address=123 Maple Street", and "creditcard=4111111111111111". It is all right there because the traffic is not encrypted.

So he has a name, phone number, address, credit card numbers, and so on. The scary part is that the victim does not get an alert. There is no pop-up that says someone is listening. The page still loads, the form still submits, and everything looks normal. That is why sending sensitive info over standard HTTP is a problem as far as security.

Why HTTPS Exists - Secure HTTP Encrypts Your Data In Transit

And this is why HTTPS was developed. HTTPS stands for Secure Hypertext Transfer Protocol, and this is HTTP with a security feature. The extra S is not cosmetic. Secure HTTP encrypts the data that is being retrieved by HTTP. The underlying web behavior stays the same, but now the contents are protected by cryptography.

Secure HTTP ensures that all the data that is being transferred over the Internet between computers and servers is secure by making the data impossible to read for anyone who does not have the proper keys. It does this by using encryption algorithms to scramble the data that is being transferred. The browser and the server agree on a key, and from that point on, everything sent across that connection is scrambled before it leaves and then unscrambled only when it reaches the other side.

So, for example, if you were to go to a website that requires you to enter personal information, such as passwords or credit card numbers, you will notice that an S will be added to the HTTP in the web address. That S indicates that you are now using Secure HTTP and have entered a secure website where sensitive data is going to be passed and that data is going to be protected.

And in addition to the S being added, a lot of web browsers will also show a padlock symbol in the address bar to indicate that Secure HTTP is being used. The padlock is usually on the left of the address. If you click it, most browsers will show a small panel with the certificate information and a note like "Connection is secure" along with the encryption details. That visual cue is there to help you quickly check that your connection is protected.

So by using Secure HTTP, all the data, which includes anything that you type, is no longer sent in clear text. It is scrambled in an unreadable form as it travels across the Internet. So if a hacker were to try and steal your information, he would get a bunch of meaningless data because the data is encrypted. Without the decryption key, the captured bytes look like random characters. And the hacker would not be able to crack the encryption to unscramble the data with any realistic amount of time or computing power.

Under The Hood - The Two Protocols HTTPS Uses To Protect You

Now, Secure HTTP protects the data by using one of two protocols. And one of these protocols is SSL. The other is TLS. They work in a similar way from your point of view, and the browser chooses the best one it supports with the server when the connection starts.

SSL - Secure Sockets Layer And How The Browser Proves A Site Is Trustworthy

SSL, or Secure Sockets Layer, is a protocol that is used to ensure security on the Internet. It uses public key encryption to secure data. Public key encryption is a system where there are two keys. One is public and can be shared with anyone. One is private and must be kept secret. Data encrypted with the public key can only be decrypted with the matching private key, and vice versa.

So basically, this is how SSL works when a connection starts. When a computer connects to a website that is using SSL, the computer's web browser will ask the website to identify itself. That first message says "let us talk securely" and lists the encryption methods the browser supports. Then the web server will send the computer a copy of its SSL certificate.

An SSL certificate is a small digital certificate that is used to authenticate the identity of a website. It contains the website's public key and details like the domain name it is valid for, the organization name if the certificate includes that, the issuer who signed it, and the validity period with start and end dates. Basically, it is used to let your computer know that the website you are visiting is trustworthy. The browser looks at the certificate and checks whether it was issued by a certificate authority that the browser trusts.

So then the computer's browser will check to make sure that it trusts the certificate. And if it does, it will send a message to the web server. That message includes key agreement data that lets both sides create the same secret session key while never sending that key in plain text. Then after, the web server will respond back with an acknowledgement, so an SSL session can proceed.

The SSL Handshake - Step By Step In Plain Language

Your browser says hello and offers encryption options it supports.
The server replies with its choice of options and sends its SSL certificate.
Your browser verifies the certificate as described above. If it trusts it, it continues.
Using the server's public key, your browser helps establish a shared secret that only the server with the private key can understand.
Both sides confirm that they derived the same secret and switch to encrypted communication using that session key.

Then, after all these steps are complete, encrypted data can now be exchanged between your computer and the web server. From that point on, anyone capturing the traffic sees encrypted packets. The actual text of your login, your card details, and your browsing session is hidden behind the encryption layer.

TLS - Transport Layer Security, The Successor To SSL

And the other protocol that Secure HTTP can use is called TLS. TLS, or Transport Layer Security, is the latest industry standard cryptographic protocol. It is the successor to SSL and it is based on the same specifications. From your perspective in the browser, it does the same job. It just does it with updated algorithms, tighter security, and improvements to the handshake.

Like SSL, it also authenticates the server, authenticates the client when needed, and encrypts the data. When your browser connects to a modern website, it typically uses TLS automatically. The padlock and the https in the address bar look the same. Behind the scenes, TLS handles the key exchange, sets up a session key, and encrypts every request and response. If you clicked the lock and opened the connection details, you would see something like TLS 1.2 or TLS 1.3 along with the cipher suite that was agreed on.

The key point is this. Whether the site says SSL in documentation or people are casually saying SSL, the actual protocol in use on current sites is TLS, which is the evolution of SSL. The logic stays the same - authenticate the site, then protect the data with encryption - and your browser manages the whole process automatically once you hit a secure site.

Seeing HTTPS In The Real World - The S, The Padlock, And What Browsers Do

When you go to a website that requires personal information, you will notice that the URL starts with https and not plain http. That S is your shorthand that encryption is active. The address bar padlock is the visual assurance. If you click it, you can view certificate details, including the issuer and validity. If there is any mismatch or problem, modern browsers warn loudly with a full-page interstitial saying the connection is not private.

Some pages also display mixed content warnings if part of the page is loaded over plain HTTP. That is because a secure page should not pull images or scripts from insecure origins. When everything is correctly set up, the lock remains closed, the scheme is https, and the entire page load is encrypted end to end.

It is also useful to know that many sites redirect you automatically. If you type http, the server will send you to https before anything sensitive is exchanged. That redirect is normal, and it is part of how sites make sure all visitors end up protected even if they forgot to type the S themselves.

Why Many Sites Use Secure HTTP Everywhere Now

It is also important to point out that a lot of websites are now using Secure HTTP by default on their websites, regardless of whether sensitive data is going to be exchanged or not. The reason is simple. Encryption protects login pages, but it also protects cookies, search queries, and page content from being tampered with in transit. It prevents someone on the path from injecting ads or malware into the page. And it gives users a consistent, safe experience from the first click.

A lot of this has to do with Google. Google is now flagging websites as not secure if they are not protected with SSL. In Chrome, for example, a site that is plain HTTP will show "Not secure" in the address bar, especially on pages with forms. That label is not subtle. It tells users exactly what is going on. And it influences whether people feel comfortable using the site.

And if a website is not SSL protected, Google will penalize that website in their search rankings. Security is one of many signals, and sites that adopt HTTPS everywhere get a boost compared to similar sites that do not. Because of that, and because user trust matters, most major sites have moved to HTTPS by default. So that is why now, if you go to any major website, you will notice that Secure HTTP is being used rather than standard HTTP.

What It Takes To Secure Your Own Site With An SSL Certificate

If you are interested in getting an SSL certificate for your website, there are a few simple ideas to have in mind so the plan is clear end to end. An SSL certificate is the piece that lets browsers authenticate your site and start encryption. You choose a certificate that matches your domain, install it on your server, configure your web server to listen on port 443 for https, and set up a redirect from http to https so visitors always land on the secure version. Once it is installed correctly, your site will show the https scheme and the padlock automatically.

There are different ways to get a certificate. Many hosts provide tools in the control panel to request and install one in a few clicks. Some developers prefer to generate a certificate signing request on the server and complete the process manually. Either way, the goal is the same - a valid certificate issued by a trusted certificate authority that matches your domain and passes the browser checks we talked about earlier.

If you are interested in getting an SSL certificate for your website, I do have a link in the description below for an up to 30 percent discount on SSL certificates, domain names, or website. That offer is useful if you are buying hosting and a certificate together or if you want to secure several domains with a multi-domain certificate. Use the link, pick the option that matches your setup, and then complete the install in your hosting panel or web server. After that, test your site by visiting it with https and looking for the padlock and the secure connection details.

Putting It All Together - From Plain HTTP To Secure HTTPS With SSL-TLS

Let us recap the exact flow we walked through and keep it in the same sequence you will encounter in the browser:

HTTP is the Hypertext Transfer Protocol, probably the most widely used protocol for loading web pages.
Standard HTTP sends all the information in clear text, which makes it readable to anyone who can intercept it along the path from your device to the server.
That includes anything you type - name, phone number, address, passwords, and credit card information - if you send it over plain HTTP.
Because of that, a hacker on the same network or somewhere on the Internet can listen in as data is transferred and steal your information.
HTTPS was developed to solve this. It stands for Secure Hypertext Transfer Protocol and adds encryption on top of HTTP.
When you see https in the URL and a padlock in the address bar, the browser has set up an encrypted channel so anything you type is scrambled in an unreadable form.
HTTPS uses SSL or TLS to do the encryption and to authenticate the website with a certificate your browser trusts.
The SSL-TLS handshake includes the browser asking the site to identify itself, the server sending its certificate, the browser verifying it, and both sides agreeing on a secret session key before exchanging encrypted data.
Modern sites use TLS as the successor to SSL. It is based on the same specifications and protects your data in the same way from your point of view.
Most websites now use Secure HTTP by default. Google marks sites that are not protected as not secure and penalizes them in search rankings, so you will see https on major sites almost all the time.
If you run a site, you can get an SSL certificate and enable https. There is a link in the description below with up to a 30 percent discount on SSL certificates, domain names, or website to help you get started.

Conclusion - Check For The S, Look For The Lock, Protect Your Data

Now you have seen exactly why that S in https matters and what the padlock in your address bar is telling you. Standard HTTP sends data in clear text, which makes it vulnerable to anyone who wants to capture and read it as it travels over the public Internet. Secure HTTP encrypts your data so a hacker would only see meaningless gibberish, not your name, phone number, address, password, or card number.

SSL and TLS are the protocols that make this protection real. Your browser asks the site to identify itself, checks the SSL certificate to confirm it is trustworthy, and only then begins sending encrypted data back and forth. That is why so many websites now use Secure HTTP by default, and that is why Google flags non-secure sites and lowers their search ranking. If you are running a website, use the link in the description below for up to 30 percent off SSL certificates, domain names, or website and get your visitors protected. If you are browsing, keep an eye on that S and the padlock, and you will know when your connection is secure.