Decode Base64 Online

Common Uses for Base64 Decoding

Base64 encoded data appears everywhere in software development: Kubernetes Secrets (stored as Base64), JWT token payloads, email attachments (MIME encoding), data URIs in CSS and HTML, and API responses that encode binary data as text.

Our decoder handles standard Base64 (RFC 4648), URL-safe Base64 (used in JWTs, where +// are replaced with -/_), and padded/unpadded variants. Paste in the encoded string and get the decoded text instantly — everything runs in your browser.

This is essential for debugging authentication (read JWT claims without a dedicated JWT tool), inspecting Kubernetes secrets (kubectl get secret -o jsonpath returns Base64), and verifying data integrity (decode and check the content matches expectations).

Tips

• Base64 is encoding, not encryption — it provides zero security. Anyone can decode it.
• If decoded output looks like garbage, the original data might be binary (image, PDF) rather than text.
• Kubernetes secrets: echo "encoded_value" | base64 -d in terminal, or paste here for quick inspection.
• Base64 strings are always divisible by 4 in length (with = padding). If not, add padding to fix decode errors.