diff --git a/Pipfile b/Pipfile
index fe501af..e23969c 100644
--- a/Pipfile
+++ b/Pipfile
@@ -37,6 +37,7 @@ numpy = "*"
 warcio = "*"
 jsonlines = "*"
 pysubs2 = "*"
+minify-html = "*"
 
 [dev-packages]
 autopep8 = "*"
diff --git a/Pipfile.lock b/Pipfile.lock
index 0a46b69..75c92f9 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "1214bb42dd8bf964abf6ea24a960973433411a0ffa442b9a3fa7beb0e77faed2"
+            "sha256": "e69d35bafb350b93cc5817b80b215c54e9df7454722684bd3c2dd8c5a750424c"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -266,7 +266,7 @@
                 "sha256:fd5f17ff8f14003595ab414e45fce13d073e0762394f957182e69035c9f3d7c2",
                 "sha256:fdc3ff3bfccdc6b9cc7c342c03aa2400683f0cb891d46e94b64a197910dc4064"
             ],
-            "markers": "implementation_name == 'cpython'",
+            "markers": "platform_python_implementation >= 'CPython'",
             "version": "==1.1.0"
         },
         "bs4": {
@@ -643,11 +643,11 @@
         },
         "google-api-core": {
             "hashes": [
-                "sha256:08ed79ed8e93e329de5e3e7452746b734e6bf8438d8d64dd3319d21d3164890c",
-                "sha256:de7ef0450faec7c75e0aea313f29ac870fdc44cfaec9d6499a9a17305980ef66"
+                "sha256:610c5b90092c360736baccf17bd3efbcb30dd380e7a6dc28a71059edb8bd0d8e",
+                "sha256:9df18a1f87ee0df0bc4eea2770ebc4228392d8cc4066655b320e2cfccb15db95"
             ],
             "markers": "python_version >= '3.7'",
-            "version": "==2.17.0"
+            "version": "==2.17.1"
         },
         "google-api-python-client": {
             "hashes": [
@@ -693,12 +693,12 @@
         },
         "gspread": {
             "hashes": [
-                "sha256:6c3af32b753fe75d9dd513ea9e088e9e043e09b9e3bf04d61d77213f37e67b79",
-                "sha256:8c8bf83be676a019d3a483455d8b17b442f2acfc620172f245422ca4fc960dd0"
+                "sha256:0238ba43f3bd45e7fa96fd206e9ceb73b03c2896eb143d7f4373c6d0cfe6fddf",
+                "sha256:0982beeb07fa3ec4482a3aaa96ca13a1e6b427a0aca4058beab4cdc33c0cbb64"
             ],
             "index": "pypi",
             "markers": "python_version >= '3.8'",
-            "version": "==6.0.1"
+            "version": "==6.0.2"
         },
         "h11": {
             "hashes": [
@@ -965,6 +965,38 @@
             "markers": "python_version >= '3.7'",
             "version": "==0.1.2"
         },
+        "minify-html": {
+            "hashes": [
+                "sha256:01ea40dc5ae073c47024f02758d5e18e55d853265eb9c099040a6c00ab0abb99",
+                "sha256:1056819ea46e9080db6fed678d03511c7e94c2a615e72df82190ea898dc82609",
+                "sha256:2a9aef71b24c3d38c6bece2db3bf707443894958b01f1c27d3a6459ba4200e59",
+                "sha256:3b38ea5b446cc69e691a0bf64d1160332ffc220bb5b411775983c87311cab2c7",
+                "sha256:40f38ddfefbb63beb28df20c2c81c12e6af6838387520506b4eceec807d794a3",
+                "sha256:597c86f9792437eee0698118fb38dff42b5b4be6d437b6d577453c2f91524ccc",
+                "sha256:5f707b233b9c163a546b15ce9af433ddd456bd113f0326e5ffb382b8ee5c1a2d",
+                "sha256:70251bd7174b62c91333110301b27000b547aa2cc06d4fe6ba6c3f11612eecc9",
+                "sha256:7a5eb7e830277762da69498ee0f15d4a9fa6e91887a93567d388e4f5aee01ec3",
+                "sha256:7af72438d3ae6ea8b0a94c038d35c9c22c5f8540967f5fa2487f77b2cdb12605",
+                "sha256:7b071ded7aacbb140a7e751d49e246052f204b896d69663a4a5c3a27203d27f6",
+                "sha256:7b2aadba6987e6c15a916a4627b94b1db3cbac65e6ae3613b61b3ab0d2bb4c96",
+                "sha256:7e6d4f97cebb725bc1075f225bdfcd824e0f5c20a37d9ea798d900f96e1b80c0",
+                "sha256:92375f0cb3b4074e45005e1b4708b5b4c0781b335659d52918671c083c19c71e",
+                "sha256:a23a8055e65fa01175ddd7d18d101c05e267410fa5956c65597dcc332c7f91dd",
+                "sha256:afd76ca2dc9afa53b66973a3a66eff9a64692811ead44102aa8044a37872e6e2",
+                "sha256:b6356541799951c5e8205aabf5970dda687f4ffa736479ce8df031919861e51d",
+                "sha256:bd682207673246c78fb895e7065425cc94cb712d94cff816dd9752ce014f23e8",
+                "sha256:cda674cc68ec3b9ebf61f2986f3ef62de60ce837a58860c6f16b011862b5d533",
+                "sha256:cf4c36b6f9af3b0901bd2a0a29db3b09c0cdf0c38d3dde28e6835bce0f605d37",
+                "sha256:d4c4ae3909e2896c865ebaa3a96939191f904dd337a87d7594130f3dfca55510",
+                "sha256:dc2df1e5203d89197f530d14c9a82067f3d04b9cb0118abc8f2ef8f88efce109",
+                "sha256:e47197849a1c09a95892d32df3c9e15f6d0902c9ae215e73249b9f5bca9aeb97",
+                "sha256:ea315ad6ac33d7463fac3f313bba8c8d9a55f4811971c203eed931203047e5c8",
+                "sha256:ef6dc1950e04b7566c1ece72712674416f86fef8966ca026f6c5580d840cd354",
+                "sha256:f37ce536305500914fd4ee2bbaa4dd05a039f39eeceae45560c39767d99aede0"
+            ],
+            "index": "pypi",
+            "version": "==0.15.0"
+        },
         "multidict": {
             "hashes": [
                 "sha256:01265f5e40f5a17f8241d52656ed27192be03bfa8764d88e8220141d1e4b3556",
@@ -1742,7 +1774,7 @@
                 "sha256:c97dfde1f7bd43a71c8d2a58e369e9b2bf692d1334ea9f9cae55add7d0dd0f84",
                 "sha256:fdb6d215c776278489906c2f8916e6e7d4f5a9b602ccbcfdf7f016fc8da0596e"
             ],
-            "markers": "python_version >= '3.7'",
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4, 3.5'",
             "version": "==2.0.7"
         },
         "vk-api": {
@@ -1844,7 +1876,7 @@
                 "sha256:fc4e7fa5414512b481a2483775a8e8be7803a35b30ca805afa4998a84f9fd9e8",
                 "sha256:ffefa1374cd508d633646d51a8e9277763a9b78ae71324183693959cf94635a7"
             ],
-            "markers": "python_version >= '3.8'",
+            "markers": "python_version >= '3.7'",
             "version": "==12.0"
         },
         "werkzeug": {
diff --git a/src/auto_archiver/formatters/html_formatter.py b/src/auto_archiver/formatters/html_formatter.py
index 7202a0b..3449a0a 100644
--- a/src/auto_archiver/formatters/html_formatter.py
+++ b/src/auto_archiver/formatters/html_formatter.py
@@ -4,6 +4,7 @@ import mimetypes, os, pathlib
 from jinja2 import Environment, FileSystemLoader
 from urllib.parse import quote
 from loguru import logger
+import minify_html
 
 from ..version import __version__
 from ..core import Metadata, Media, ArchivingContext
@@ -45,6 +46,8 @@ class HtmlFormatter(Formatter):
             metadata=item.metadata,
             version=__version__
         )
+        content = minify_html.minify(content, minify_js=False, minify_css=True)
+
         html_path = os.path.join(ArchivingContext.get_tmp_dir(), f"formatted{random_str(24)}.html")
         with open(html_path, mode="w", encoding="utf-8") as outf:
             outf.write(content)
diff --git a/src/auto_archiver/formatters/templates/html_template.html b/src/auto_archiver/formatters/templates/html_template.html
index eb23bf1..93dc43a 100644
--- a/src/auto_archiver/formatters/templates/html_template.html
+++ b/src/auto_archiver/formatters/templates/html_template.html
@@ -96,6 +96,11 @@
             overflow: hidden;
             background-color: #f1f1f1;
         }
+
+        .pem-certificate {
+            text-align: left;
+            font-size: small;
+        }
     </style>
 </head>
 
@@ -184,7 +189,45 @@
     <p style="text-align:center;">Made with <a
             href="https://github.com/bellingcat/auto-archiver">bellingcat/auto-archiver</a> v{{ version }}</p>
 </body>
+<script src="https://cdnjs.cloudflare.com/ajax/libs/forge/0.10.0/forge.min.js" defer></script>
 <script defer>
+    // partial decode of SSL certificates
+    function decodeCertificate(sslCert) {
+        var cert = forge.pki.certificateFromPem(sslCert);
+        return `PREVIEW:<br/><ul>
+            <li><b>Subject:</b> <span class="copy">${cert.subject.attributes.map(attr => `${attr.shortName}: ${attr.value}`).join(", ")}</span></li>
+            <li><b>Issuer:</b> <span class="copy">${cert.issuer.attributes.map(attr => `${attr.shortName}: ${attr.value}`).join(", ")}</span></li>
+            <li><b>Valid From:</b> <span class="copy">${cert.validity.notBefore}</span></li>
+            <li><b>Valid To:</b> <span class="copy">${cert.validity.notAfter}</span></li>
+            <li><b>Serial Number:</b> <span class="copy">${cert.serialNumber}</span></li>
+        </ul>`;
+    }
+
+    async function run() {
+        await PreviewCertificates();
+        await enableCopyLogic();
+        await enableCollapsibleLogic();
+        await setupSafeView();
+    }
+
+    async function PreviewCertificates() {
+        await Promise.all(
+            Array.from(document.querySelectorAll(".pem-certificate")).map(async el => {
+                let certificate = await (await fetch(el.getAttribute("pem"))).text();
+                el.innerHTML = decodeCertificate(certificate);
+
+                let cyberChefUrl =
+                    `https://gchq.github.io/CyberChef/#recipe=Parse_X.509_certificate('PEM')&input=${btoa(certificate)}`;
+                // create a new anchor with this url and append after the code
+                let a = document.createElement("a");
+                a.href = cyberChefUrl;
+                a.textContent = "Full certificate details";
+                el.parentElement.appendChild(a);
+            })
+        );
+        console.log("certificate preview done");
+    }
+
     // notification logic
     const notification = document.getElementById("notification");
 
@@ -198,83 +241,95 @@
     }
 
     // copy logic
-    Array.from(document.querySelectorAll(".copy")).forEach(el => {
-        el.onclick = () => {
-            document.execCommand("copy");
-        }
-        el.addEventListener("copy", (e) => {
-            e.preventDefault();
-            if (e.clipboardData) {
-                if (el.hasAttribute("copy-value")) {
-                    e.clipboardData.setData("text/plain", el.getAttribute("copy-value"));
-                } else {
-                    e.clipboardData.setData("text/plain", el.textContent);
+    async function enableCopyLogic() {
+        await Promise.all(
+            Array.from(document.querySelectorAll(".copy")).map(el => {
+                el.onclick = () => {
+                    document.execCommand("copy");
                 }
-                console.log(e.clipboardData.getData("text"))
-                showNotification("copied!")
-            }
-        })
-    })
+                el.addEventListener("copy", (e) => {
+                    e.preventDefault();
+                    if (e.clipboardData) {
+                        if (el.hasAttribute("copy-value")) {
+                            e.clipboardData.setData("text/plain", el.getAttribute("copy-value"));
+                        } else {
+                            e.clipboardData.setData("text/plain", el.textContent);
+                        }
+                        console.log(e.clipboardData.getData("text"))
+                        showNotification("copied!")
+                    }
+                })
+            })
+        )
+        console.log("copy logic enabled");
+    }
 
     // collapsibles
-    let coll = document.getElementsByClassName("collapsible");
-    let i;
-
-    for (i = 0; i < coll.length; i++) {
-        coll[i].addEventListener("click", function () {
-            this.classList.toggle("active");
-            // let content = this.nextElementSibling;
-            let content = this.parentElement.querySelector(".collapsible-content");
-            if (content.style.display === "block") {
-                content.style.display = "none";
-            } else {
-                content.style.display = "block";
-            }
-        });
+    async function enableCollapsibleLogic() {
+        let coll = document.getElementsByClassName("collapsible");
+        for (let i = 0; i < coll.length; i++) {
+            await new Promise(resolve => {
+                coll[i].addEventListener("click", function () {
+                    this.classList.toggle("active");
+                    // let content = this.nextElementSibling;
+                    let content = this.parentElement.querySelector(".collapsible-content");
+                    if (content.style.display === "block") {
+                        content.style.display = "none";
+                    } else {
+                        content.style.display = "block";
+                    }
+                });
+                resolve();
+            })
+        }
+        console.log("collapsible logic enabled");
     }
 
-    // logic for enabled/disabled greyscale
-    // Get references to the checkboxes and images/videos
-    const safeImageViewCheckbox = document.getElementById('safe-media-view');
-    const imagesVideos = document.querySelectorAll('img, video');
+    async function setupSafeView() {
+        // logic for enabled/disabled greyscale
+        // Get references to the checkboxes and images/videos
+        const safeImageViewCheckbox = document.getElementById('safe-media-view');
+        const imagesVideos = document.querySelectorAll('img, video');
 
-    // Function to toggle grayscale effect
-    function toggleGrayscale() {
+        // Function to toggle grayscale effect
+        function toggleGrayscale() {
+            imagesVideos.forEach(element => {
+                if (safeImageViewCheckbox.checked) {
+                    // Enable grayscale effect
+                    element.style.filter = 'grayscale(1)';
+                    element.style.webkitFilter = 'grayscale(1)';
+                } else {
+                    // Disable grayscale effect
+                    element.style.filter = 'none';
+                    element.style.webkitFilter = 'none';
+                }
+            });
+        }
+
+        // Add event listener to the checkbox to trigger the toggleGrayscale function
+        safeImageViewCheckbox.addEventListener('change', toggleGrayscale);
+
+        // Handle the hover effect using JavaScript
         imagesVideos.forEach(element => {
-            if (safeImageViewCheckbox.checked) {
-                // Enable grayscale effect
-                element.style.filter = 'grayscale(1)';
-                element.style.webkitFilter = 'grayscale(1)';
-            } else {
-                // Disable grayscale effect
+            element.addEventListener('mouseenter', () => {
+                // Disable grayscale effect on hover
                 element.style.filter = 'none';
                 element.style.webkitFilter = 'none';
-            }
+            });
+
+            element.addEventListener('mouseleave', () => {
+                // Re-enable grayscale effect if checkbox is checked
+                if (safeImageViewCheckbox.checked) {
+                    element.style.filter = 'grayscale(1)';
+                    element.style.webkitFilter = 'grayscale(1)';
+                }
+            });
         });
+        toggleGrayscale();
+        console.log("grayscale logic enabled");
     }
 
-    // Add event listener to the checkbox to trigger the toggleGrayscale function
-    safeImageViewCheckbox.addEventListener('change', toggleGrayscale);
-
-    // Handle the hover effect using JavaScript
-    imagesVideos.forEach(element => {
-        element.addEventListener('mouseenter', () => {
-            // Disable grayscale effect on hover
-            element.style.filter = 'none';
-            element.style.webkitFilter = 'none';
-        });
-
-        element.addEventListener('mouseleave', () => {
-            // Re-enable grayscale effect if checkbox is checked
-            if (safeImageViewCheckbox.checked) {
-                element.style.filter = 'grayscale(1)';
-                element.style.webkitFilter = 'grayscale(1)';
-            }
-        });
-    });
-
-    // Call the function on page load to apply the initial state
-    toggleGrayscale();
+    run();
 </script>
 
 </html>
\ No newline at end of file
diff --git a/src/auto_archiver/formatters/templates/macros.html b/src/auto_archiver/formatters/templates/macros.html
index 54da7f7..0590b37 100644
--- a/src/auto_archiver/formatters/templates/macros.html
+++ b/src/auto_archiver/formatters/templates/macros.html
@@ -41,6 +41,10 @@ No URL available for {{ m.key }}.
 </div>
 {% elif m.filename | get_extension == ".wacz" %}
 <a href="https://replayweb.page/?source={{ url | quote }}#view=pages&url={{ main_url }}">replayweb</a>
+
+{% elif m.filename | get_extension == ".pem" %}
+<code class="pem-certificate" pem="{{url}}"></code>
+
 {% else %}
 No preview available for {{ m.key }}.
 {% endif %}