ASCII
Before
SGVsbG8=
After
Hello
Base64 Decode
Decode Base64 strings from API responses, config files, and JWT segments back into readable UTF-8 text.
Base64 Decode
Decodes Base64 — invalid input shows a friendly error.
Base64 string to decode
Original decoded text
Input: 0 chars
Output: 0 chars
Status: ready
Your text stays in your browser — nothing is uploaded.
How to Use
- Paste a Base64 string—padding optional depending on source.
- Read decoded UTF-8 text in the output panel.
- Check for error messages if the input contains invalid characters.
- Copy decoded content or re-encode after editing.
Example
Base64 input
SGVsbG8sIOS4lueVjCE=
Decoded text
Hello, 世界!
Before and After Examples
Unicode
Before
Y2Fmw6k=
After
café
Phrase
Before
SGVsbG8sIFdvcmxk
After
Hello World
Padded
Before
YQ==
After
a
What This Tool Does
Base64 Decode converts ASCII Base64 alphabet strings back into original UTF-8 text bytes. It validates character sets and padding, surfacing errors when strings are truncated or corrupted—common when copy-paste drops trailing equals signs.
Guidelines
Tip
Reading JWT payload segments during debugging
Practice
Inspecting Base64 fields in JSON API responses
Use case
Recovering embedded config values from DevOps templates
Note
Decoding email MIME body parts pasted from logs
Common Uses
Best Practices
Paste a Base64 string—padding optional dependin…
Read decoded UTF-8 text in the output panel.
Check for error messages if the input contains …
Copy decoded content or re-encode after editing.
Reading JWT payload segments during debugging
Inspecting Base64 fields in JSON API responses
Recovering embedded config values from DevOps t…
Decoding email MIME body parts pasted from logs
Popular Workflows
Notes & Limitations
All processing runs locally in your browser. Results may vary with edge-case characters or very large inputs.
Frequently Asked Questions
What if decoding shows gibberish?
The source may be binary data or compressed content, not UTF-8 text.
Are line breaks in Base64 OK?
Many tools ignore whitespace; remove stray newlines if decoding fails.
Can I decode URL-safe Base64?
Variants using - and _ may need conversion to standard alphabet first.
Does invalid input crash the page?
Errors display in the output area without affecting other browser tabs.