What's the maximum number of files I can convert at once?

Free users can convert several files per batch. PRO users enjoy unlimited batch sizes. For very large batches, your device's memory is the only practical limit.

Why choose DER over other formats?

DER Certificate offers compact binary encoding, used by Java and Windows. It's widely used for Java KeyStore, Windows certificate store and binary cert distribution, making it an excellent choice for most certificate needs.

Will my CER file be deleted after conversion?

No. Your original CER file is never modified or deleted. Xonvert creates a separate DER copy — your source file remains untouched.

What certificate quality settings should I use?

Default settings are optimized for the best balance of quality and file size. Adjust only if you have specific requirements.

Does this work on my phone or tablet?

Yes. Xonvert works on any device with a modern browser — iPhone, iPad, Android phones and tablets all supported.

Can I undo a conversion?

Since your original CER file is never modified, there's nothing to undo. Your source file remains exactly as it was — only a new DER copy is created.

What if my CER file won't convert?

Ensure the file isn't corrupted or DRM-protected. Try a different file to verify. If issues persist, the file may use an unsupported codec variant.

Convert CER to DER

Fast, free, and secure CER to DER conversion. No registration required.

cer

der

Certificate

Fast, free, and secure CER to DER conversion. No registration required.

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Related Conversions

PEM→DER

CRT→DER

High Quality

Maintain maximum quality during conversion

Fast Processing

Convert files in seconds with our optimized engine

Secure & Private

Files automatically deleted after conversion

How to Convert CER to DER

Upload CER File

Click the "Select File" button to upload your cer file from your device.

Start Conversion

Click the "Convert" button to instantly start converting to DER.

Download DER

Download your converted der file immediately after processing.

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