Does Base64 Encoder Decoder upload my input?

No. This tool runs in your browser unless the privacy badge explicitly says a server route is required.

Can I use this for production secrets?

Avoid pasting sensitive production data into any website. Prefer local test data or redacted payloads.

Why does decoded Base64 look unreadable?

The decoded bytes may be binary, compressed, encrypted, or not UTF-8 text. Treat unreadable output as a signal, not a failure.

When should I use Base64URL mode?

Use Base64URL for JWT segments, URL-safe tokens, and values that replace plus and slash with URL-safe characters.

Base64 Encoder Decoder - Free Online Base64 and Image Data URL Tool

base64 encoderbase64 decoderdecode base64encode base64Privacy: Browser local

Base64 Encoder Decoder

Encode, decode, inspect, and copy a safe payload report for Base64, Base64URL, image data URLs, JSON payloads, and JWT segments locally in the browser.

Input / Output

Start with the tool

Input, output, and copy actions stay in this main surface. Examples and reference checks are separated below.

Copy-ready output

Base64 examples

Text or Base64Mode

Input bytes

Output characters

Padding characters

Base64 variant

Standard Base64

Output variants

Copy the standard value for headers and storage, or URL-safe value for path and token segments.

text

URL-safe Base64

aGVsbG8gd29ybGQ

Base64 diagnostics

Check decoded shape, JSON keys, line count, and control characters before copying the value.

text

Detected content

text

Text lines

JSON keys

Control characters

Review notes

- No obvious Base64 issues detected for this input.

Base64 payload report

Copy a compact handoff report with Base64 variant, decoded shape, review notes, and safe sharing checks.

Mode

Encode UTF-8 to Base64

Detected content

text

Input bytes

Output characters

Padding characters

JSON keys

Review notes

No obvious Base64 issues detected. Still redact secrets before sharing.

Safe handoff checklist

Redact tokens, cookies, passwords, and customer identifiers before sharing decoded text.
Confirm whether the target expects standard Base64 or URL-safe Base64 before copying.
If decoded content is JSON, inspect it in JSON Formatter before attaching it to a ticket.
If decoded content looks like a JWT segment, use JWT Decoder for token context.
If the output is binary or an image, share the data URL or file preview instead of raw text.

# Base64 payload report

- Checked at: Browser copy time
- Mode: Encode UTF-8 to Base64
- Base64 variant: Standard Base64
- Detected content: text
- Input bytes: 11
- Output characters: 16
- Padding characters: 1
- Text lines: 1
- JSON keys: 0
- Control characters: 0

## Review notes
- No obvious Base64 issues detected. Still redact secrets before sharing.

## Safe handoff checklist
- Redact tokens, cookies, passwords, and customer identifiers before sharing decoded text.
- Confirm whether the target expects standard Base64 or URL-safe Base64 before copying.
- If decoded content is JSON, inspect it in JSON Formatter before attaching it to a ticket.
- If decoded content looks like a JWT segment, use JWT Decoder for token context.
- If the output is binary or an image, share the data URL or file preview instead of raw text.

Output

Encode UTF-8 to Base64

Copy-ready output

aGVsbG8gd29ybGQ=

Local session

Input state is saved only in this browser so you can restore the last workspace without an account.

Review after the result

Open examples, checks, and related tools only after the primary input/output flow is done.

Web operations workbench

Inspect an image data URL

Preview Base64 image data, confirm the MIME type, then check presentation contrast before sharing.

3 Tools

1. Base64
Detect image bytes and preview the data URL without copying binary text.
2. MIME
Confirm the extension and content type used by the image.
3. Color
Check contrast when the image is used in a QR, badge, or document background.

Decode an API token

Inspect JWT claims, check time fields, and compare encoded segments safely.

3 Tools

1. JWT
Read header and payload, compare expected claims, and copy an auth report without sending the token to a verifier.
2. Timestamp
Convert exp, iat, and nbf values into readable dates.
3. Base64
Compare Base64URL segments, padding issues, and copy a payload report when token context is unclear.

Verify a webhook signature

Generate the HMAC output, copy a safe signature report, and inspect payload shape or encoding before changing webhook code.

3 Tools

1. Hash
Generate digest or HMAC output and copy the signature report without raw input or secrets.
2. JSON
Check whether the webhook body shape or whitespace changed before signing.
3. Base64
Inspect Base64 or Base64URL encoded bodies and signatures when the webhook provider uses encoded values.

Before copying

Choose encode or decode mode deliberately before pasting the value.
Confirm the decoded text is expected UTF-8, not binary or compressed data.
Use the diagnostics panel to check JSON keys, JWT-like payloads, padding, and control characters.

Common failure cases

URL-safe Base64 and standard Base64 can differ by padding and character set.
Binary data may not round-trip as readable UTF-8 text.

Guides

A practical workflow for browser-based developer utilities

Review after the result

Open examples, checks, and related tools only after the primary input/output flow is done.

Guides

Examples

Starting points for this utility

hello worldSGVsbG8sIEJvYiE=data:image/png;base64,iVBORw0KGgo=

Use cases

Data

Decode copied Base64 payloads from logs
Copy a Base64 payload report with variant, decoded shape, warnings, and safe handoff checks
Preview and download Base64 image data URLs before copying binary output

Choose encode or decode mode deliberately before pasting the value.
Confirm the decoded text is expected UTF-8, not binary or compressed data.
Use the diagnostics panel to check JSON keys, JWT-like payloads, padding, and control characters.