PEM Decoder: Decode PEM Certificates, Keys, and CSRs
PEM Decoder reads a PEM block, extracts its BEGIN/END label, and base64-decodes the body into raw DER bytes. It identifies the detected type and displays a hex dump of the first 64 bytes, making certificates, public or private keys, and CSRs easier to inspect. Paste or drop PEM input; no conversion options are specified.
The PEM Decoder is a browser-based PEM Decoder for inspecting PEM-encoded certificates, public and private keys, and certificate signing requests (CSRs). It extracts the label from a PEM block, decodes the Base64 body into raw DER bytes, and presents a hex dump so you can examine the decoded data without openssl.
A PEM block uses BEGIN and END lines to mark its contents. The decoder reads the label from those lines, base64-decodes the body, identifies the detected type, and displays the first 64 decoded bytes as hexadecimal. The tool's described output is for inspection; no additional conversion options are specified.
PEM represents data in a text-friendly form, while DER is the raw byte representation produced by decoding the PEM body. Converting PEM to DER bytes can help when you need to inspect the underlying data in a hex dump or work with a certificate, key, or CSR outside its text-encoded form. The displayed hex dump is limited to the first 64 bytes.
The PEM Decoder runs entirely in your browser. Your input is processed on your device and is not uploaded, stored, or sent to a server; after the page loads, the tool also works offline. It is free to use, so you can inspect PEM data without sending it to an online service.
This tool is useful for developers and DevOps engineers who need to examine PEM certificates, keys, or CSRs, whether they are new to these formats or already work with them regularly. Paste or drop a PEM value to view its detected type and decoded bytes.
Step 1: Paste or drop your PEM value into the input area. Include the complete block, from its -----BEGIN…----- line through its matching -----END…----- line.
Step 2: Run the decode to extract the PEM label and base64-decode the block body into raw DER bytes.
Step 3: Review the detected type and the hex dump, which displays the first 64 decoded bytes.
Step 4: Copy the recovered result if you need to use or keep the decoded output.
Use case: Inspect a certificate PEM value received from a teammate by checking its detected type and decoded bytes.
Use case: Examine a public or private key PEM block without using openssl to decode its body.
Use case: Review a certificate signing request (CSR) PEM block and see its label and the first 64 DER bytes.
Use case: When a text-only channel carries a PEM value, decode the received block to inspect its raw DER bytes.
Use case: Check the label and encoded body of a PEM block when investigating certificate or key data.
Use case: Quickly view a PEM block's decoded bytes in a hex dump when working in a browser.