Free PEM and JWK key converter
Convert key formats locally so private keys never leave your machine.
How to use this tool
- 1
Open Key format converter
Use it for this task: RSA PEM to JWK, JWK to PEM, auto-detect key format, Web Crypto local conversion.
- 2
Paste a key
Add a PEM, JWK, or supported key block, then choose the target format.
- 3
Validate and copy the converted key
Review the detected key type and copy the converted output into your local tooling.
Quick facts
| Runs locally? | Yes. Processing stays in your browser. |
|---|---|
| Uploads data? | No. Files and text are not sent to our servers. |
| Account required? | No signup or login. |
| Best for | JWT keys, OAuth, SSH checks, backend config |
Top use cases
- RSA PEM to JWK, JWK to PEM, auto-detect key format, Web Crypto local conversion.
- Runs locally?: Yes. Processing stays in your browser.
- Uploads data?: No. Files and text are not sent to our servers.
- Account required?: No signup or login.
- Best for: JWT keys, OAuth, SSH checks, backend config
FAQ
Does this tool upload my data?▾
No. The tool runs in your browser tab and does not send your input to our servers.
Can I use it offline?▾
After the app loads and the service worker is active, many tool pages can reopen without a network connection.
Is it free?▾
Yes. It is free to use and does not require an account.
What limits should I expect?▾
The practical limit is your device memory and browser performance, especially for large files.
Can I use this for sensitive data?▾
Yes for local processing, but always verify outputs before using them in critical workflows.
Which browsers work best?▾
Current Chrome, Edge, Firefox, and Safari versions work best for local file and crypto APIs.