Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 into readable text instantly with this free online tool.
Convert plain text to Base64 or decode Base64 back into readable text. Unicode, emojis and URL-safe output are supported, and everything runs in your browser without an account or an external API.
Base64 Encoder & Decoder
Convert plain text to Base64 or decode Base64 back into readable text. All conversions are processed locally in your browser.
Your text is processed locally in this browser. It is not uploaded to CoveScreen. Avoid entering passwords, access tokens, private keys, or other sensitive information into online tools.
Do not enter passwords, authentication codes, private keys, or access tokens in any field, including the editors on this page.
URL-safe Base64 replaces + and / with - and _, which avoids characters that need escaping in URLs and filenames. Padding can be omitted when the receiving system expects it.
0 characters
Up to 1.00 MB of text.
0 bytesThe encoded text will appear here.
0 characters
0 bytesPress Control + Enter (Command + Enter on macOS) to run the conversion.
Statistics
Run a conversion to see character and byte counts. The selected format is Standard Base64.
Base64 turns every three bytes into four characters, so the exact increase depends on the input length and the padding. The figure above is an estimate, not a measurement.
Encode or Decode a File
Files are converted from their bytes, never as text, and are never uploaded. Binary files such as images, PDFs and archives should be handled with the file conversion area. Text decoding assumes UTF-8, and binary data is not valid UTF-8 text, so decoding a file as text produces an error rather than corrupted output.
File to Base64
Up to 5.00 MB. The file is read in your browser and is not uploaded.
Base64 to File
Pasted Base64 may be line-wrapped. Up to 5.00 MB of decoded data. The bytes are written exactly as decoded and are never interpreted as text.
URL-safe input uses - and _ in place of + and /. Padding is optional either way.
Leave empty to use application/octet-stream.
Files from untrusted sources may be unsafe to open. This tool never previews or runs a decoded file.
How to Use the Base64 Encoder & Decoder
To encode text
- Select Encode mode.
- Enter or paste plain text into the input editor.
- Choose Standard or URL-safe Base64, and whether to keep the = padding.
- Select Encode to Base64, or press Control + Enter.
- Review the result in the output editor.
- Use Copy Output to copy the encoded text.
To decode Base64
- Select Decode mode.
- Paste the Base64 content into the input editor.
- Select the matching Base64 format. URL-safe input uses - and _ instead of + and /.
- Select Decode Base64, or press Control + Enter.
- Review the decoded text in the output editor.
- Copy the result if you need it.
To convert files
- Open the Encode or Decode a File section.
- Choose whether you are encoding a file into Base64 or decoding Base64 back into a file.
- Select a local file, or paste Base64 and enter a filename.
- Check the file size against the 5 MB limit.
- Run the conversion, then copy the Base64 or download the file.
Text or file?
Binary files such as images, PDFs and archives should be handled with the file conversion area. Text decoding assumes UTF-8, and binary data is not valid UTF-8 text, so decoding a file as text produces an error rather than corrupted output.
What Is Base64?
Base64 represents binary data using a set of printable ASCII characters: the uppercase and lowercase letters, the digits 0 to 9, the symbols + and /, and the = padding character. Because those 64 characters are safe to write in text-based formats, Base64 is used to move binary data through places that expect text, such as JSON payloads, email headers, XML, URLs and configuration files.
Base64 is an encoding scheme, not encryption and not hashing. It needs no key and no secret: anyone who can see the encoded text can decode it with this page or with a one-line script. It provides no confidentiality and no integrity, so it must never be used to protect passwords, tokens or private keys, and it cannot replace access control.
Base64 is genuinely useful for interoperability, which is why it appears in so many API contracts. When two systems disagree about character encoding, or when binary data has to travel through a text-only field, Base64 removes the ambiguity. The cost is size: encoding turns three bytes into four printable characters, so the encoded form is larger than the original and the exact increase depends on the input length and the padding.
Plain text
Hello World
Base64
SGVsbG8gV29ybGQ=
Paste either value into the tool above to confirm the round trip.
Common Use Cases
Small text values in data formats
A field that must contain only safe characters, such as a token, a short identifier or a signature fragment, can carry its value as Base64 when the receiving format expects that.
API payloads that expect Base64
Many APIs accept images, attachments and certificates as Base64 inside a JSON body instead of as multipart uploads. Encoding locally first lets you inspect exactly what will be sent.
Binary content in text-oriented systems
Email headers, XML nodes, database text columns and configuration formats all need binary data expressed in text. Base64 is the usual way to carry it.
Inspecting encoded strings during development
When an API returns an encoded value or a log line contains one, decoding it locally is the quickest way to see what it actually contains.
Troubleshooting data exchange
When two systems disagree about a value, encoding and decoding it in one place isolates the problem to the format rather than to the transport.
Test fixtures and sample payloads
Turning a binary fixture into a Base64 string lets you paste it into a test, a seed script or a documentation example.
URL-safe Base64 for tokens and filenames
JWTs and query parameters cannot carry + and / safely, so they use the URL-safe alphabet. Generating that variant locally avoids hand-editing characters and introducing errors.
Requirements differ between systems: some accept unpadded URL-safe output, some require standard padding, and some expect a specific character set before the value arrives. Check what the receiving system actually requires. Base64 is a transport format and is not a substitute for encryption, signing or access control.
Frequently asked questions
What is Base64 encoding?
Base64 is a way to represent binary data as printable text using a defined set of characters. It is often used when systems need to transport or store data in text-based formats.
Is Base64 encryption?
No. Base64 is an encoding format, not encryption. It does not require a secret key and should not be used to protect confidential information.
Can I decode Base64 back to text?
Yes, if the encoded data represents text in a compatible character encoding, such as UTF-8. Binary data should be decoded as a file or byte sequence instead.
Does this tool support emojis and other languages?
Yes. Text is converted to UTF-8 bytes before it is encoded, and decoded back from UTF-8 afterwards, so emojis and non-English scripts survive a round trip unchanged.
What is URL-safe Base64?
URL-safe Base64 replaces the + and / characters with - and _. Some applications also omit the trailing padding characters. This page can produce and read both variants.
Why does my Base64 input fail to decode?
The input may contain invalid characters, incorrect padding, a format that does not match the one selected, or bytes that do not represent valid UTF-8 text. Check the selected format and the input, and use the file area if the data is binary.
Can I encode a file into Base64?
Yes. The file is read and converted locally in your browser and is not uploaded to CoveScreen by this tool. Files up to 5 MB are supported.
Is my data uploaded to CoveScreen?
No. The conversion happens locally in the browser without sending the input or the output to CoveScreen or to any third-party service, and nothing is saved to browser storage.
Can Base64 make my data secure?
No. Base64 provides neither confidentiality nor authentication. Use appropriate encryption and access controls when protecting sensitive data.
How your data is handled
All conversions happen locally in your browser. CoveScreen does not receive the text or files you process with this tool. Base64 is an encoding format, not encryption. Do not use it to protect confidential information.
Looking for a text utility rather than a Base64 converter? Classify a support ticket by priority or build an IT asset inventory.