The encryption is identical. A free Let's Encrypt certificate and a several-hundred-dollar commercial one protect the connection exactly the same way, using the same protocols and the same key strengths. Anyone telling you otherwise is selling something.
What differs is validation depth, certificate lifetime, warranty, and support, and for most sites, none of those change the decision.
What free actually gives you
Let's Encrypt issues Domain Validation certificates: it confirms you control the domain, then issues. Automated, no cost, no account with a vendor.
On Ahosting this is included and normally issued automatically once a domain points at the server, so for most people the free certificate is not a choice they make. It is already there, and the only question is whether they noticed.
Certificates are valid for about 90 days and renew automatically around 30 days before expiry. That short lifetime is the thing people object to and it is genuinely a strength: automated renewal every couple of months fails far less often than an annual renewal depending on a human remembering.
What paid adds, honestly
Deeper validation. OV and EV certificates verify the organisation exists, not just that you control the domain. Real work is done. It is also invisible: browsers removed the special address bar treatment for EV, so a visitor cannot tell.
Longer lifetime. Typically a year, so fewer renewals. Fewer, but manual, which for many sites is worse rather than better.
A warranty. Often advertised in the hundreds of thousands or millions. It protects the end user against losses caused by the authority mis-issuing a certificate. It is not insurance for your site being compromised, and claims are rare enough that it should not drive the decision.
Support. Someone to contact when installation goes wrong. Occasionally worth real money if certificates are unfamiliar territory.
Wildcard convenience. Free wildcards exist but require DNS-based validation, which is more setup. A paid wildcard is simpler to obtain.
The case for free
It costs nothing, the encryption is the same, and renewal is automatic, which removes the single most common cause of certificate failure. Expired certificates are overwhelmingly annual commercial ones nobody renewed.
For a blog, a business site, a portfolio, a small shop, or anything where nobody has handed you a written requirement, free is the right answer and there is no meaningful trade-off.
The case for paid
Three situations, and they are narrower than the marketing suggests.
Someone requires it in writing. A payment processor, a partner, an insurer, an auditor. This is the most common legitimate reason, and it is a compliance question instead of a technical one.
The warranty matters to your risk assessment. Rare, and worth reading the terms instead of the headline number.
You want someone to call. If certificates are unfamiliar and the site is important, vendor support has value, though a host that includes free SSL and answers tickets covers much of the same ground.
Reasons that are not good reasons
"Visitors will trust it more." They cannot see the difference. Browsers display free and EV certificates identically.
"Paid is more secure." Same encryption, same key strengths.
"Free certificates are for hobby sites." A very large share of the web runs on them, including sites considerably larger than yours or mine.
"Search engines prefer paid." HTTPS is a ranking signal. The certificate's price is not.
Switching from paid to free
If a commercial certificate is coming up for renewal with no requirement behind it, switching is straightforward and there is no gap if you do it before expiry.
Let AutoSSL issue for the domain, confirm the new certificate is active on the SSL/TLS Status page, then check the site in a private window. Then stop the paid renewal.
The practical gain is not the money. It is that renewal stops being a task anyone can forget.
What actually matters more than either
Whichever you choose, three things decide whether the certificate does its job, and all three are free.
It must cover every name the site answers on, including www and any subdomain. It must not be expired. And the site must actually use it, HTTP redirected, mixed content cleared.
A free certificate correctly deployed protects visitors better than an expensive one on a site still serving half its pages over HTTP. Forcing HTTPS and fixing mixed content cover the two steps that get skipped.
If the reason you were considering a paid certificate is covering many names, Wildcard and Multi-Domain (SAN) Certificates goes into whether you still need one.
Neither kind proves anything about the site behind it, which is worth being clear about before paying for one. What an SSL Certificate Does Not Protect goes over what each guarantee actually covers.
Check what is actually installed rather than what was bought
Paid and free certificates are indistinguishable to a visitor, and they are also easy to confuse on the server after a few years.
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null \ | openssl x509 -noout -issuer -dates -subject
The issuer line tells you which one is in use. The dates tell you how long it runs, which is the practical difference: a short lifetime implies automation and a long one implies somebody must remember.
The case worth finding is a paid certificate that was bought, installed once, and has since been silently replaced by an automatic one at renewal. The purchase continues and the certificate it paid for is not the one being served.
The renewal method matters more than the price
Whichever you choose, the failure that takes a site down is a renewal that did not happen, and the two types fail differently.
An automatic certificate fails when the validation stops working: a redirect rule, a firewall, a domain that no longer points here. It fails on a schedule and retries, so there is a window during which nothing is visibly wrong.
A purchased certificate fails when a person forgets, and the notification goes to whoever bought it, who may have left.
for d in example.com www.example.com mail.example.com; do printf '%-26s %s\n' "$d" "$(echo | openssl s_client -connect "$d":443 -servername "$d" 2>/dev/null | openssl x509 -noout -enddate)" done
Monitor the expiry independently of whichever mechanism renews it. That check is what catches both failure modes, and it is the same check for both. Renewing your SSL certificate covers acting on it.
Where a purchased certificate genuinely differs
Two practical differences survive scrutiny, and neither is about encryption.
Validation depth. A certificate confirming an organisation exists requires documents and takes days, and for some business relationships that record is the point rather than the padlock.
Support and warranty. A purchased certificate comes with somebody to ask, and a stated liability figure. The figure is rarely claimed and the support occasionally matters when an installation is unusual.
What does not differ is the strength of the connection, the browser behaviour or the effect on rankings. Any argument built on those three is an argument for the cheaper option. Types of SSL certificates covers the validation levels.