📥 Input (Text to Encode)

0characters

0 Bbytes

0lines

Encoding Options

URL-Safe Base64Replace + with - and / with _ Generate Data URIInclude data:mime;base64, prefix Add Line BreaksInsert newline every 76 characters (MIME) Live EncodingEncode automatically as you type

Ready — all processing happens locally in your browser.

📤 Output (Base64)

Encoded/decoded result will appear here...

0characters

0 Bbytes

+0.0% sizechange

🖼️ Image Preview

⚡

Instant Conversion

Real-time encoding and decoding as you type. No server requests — everything runs in your browser.

📁

Any File Type

Support for images, PDFs, documents, audio, video and binary files. Browser processing supports large files subject to available memory.

🔗

URL-Safe Mode

Generate URL-safe Base64 strings that work in URLs and filenames without encoding issues.

🖼️

Data URI Support

Generate Data URIs for embedding images directly in HTML, CSS, or JavaScript.

🔒

100% Private

All processing happens locally in your browser. Your data — including files and images — never leaves your device.

📋

Multiple Export Formats

Export as plain Base64, HTML img tag, CSS background-image, or Markdown image syntax.

🌐

Embed Images in HTML

Include small images directly in HTML without additional HTTP requests for faster page loads.

🎨

CSS Background Images

Embed icons and small graphics in CSS files to reduce the number of image requests.

📧

Email Attachments

Encode files for safe transmission through email systems that support MIME text encoding.

🔌

API Data Transfer

Send binary data through JSON APIs and web services that expect string values.

💾

Database Storage

Store small files and images as text in databases that do not support binary fields directly.

🔐

Authentication Tokens

Encode credentials and tokens for HTTP Basic Authentication and JWT-style Base64url payloads.

Value	Char	Value	Char	Value	Char	Value	Char
0	A	16	Q	32	g	48	w
1	B	17	R	33	h	49	x
2	C	18	S	34	i	50	y
3	D	19	T	35	j	51	z
4	E	20	U	36	k	52	0
5	F	21	V	37	l	53	1
6	G	22	W	38	m	54	2
7	H	23	X	39	n	55	3
8	I	24	Y	40	o	56	4
9	J	25	Z	41	p	57	5
10	K	26	a	42	q	58	6
11	L	27	b	43	r	59	7
12	M	28	c	44	s	60	8
13	N	29	d	45	t	61	9
14	O	30	e	46	u	62	+
15	P	31	f	47	v	63	/

Padding: The = character is used for padding when the input length is not divisible by 3.

URL-Safe: In URL-safe Base64, + becomes - and / becomes _

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that converts binary data into a set of 64 ASCII characters (A–Z, a–z, 0–9, +, /). It was designed to safely transmit binary data through systems that only support text, such as email (MIME), URLs, and XML. The name “Base64” comes from its 64-character alphabet.

How Base64 Works

Step	Description
1. Group bytes	Take 3 bytes (24 bits) of input at a time.
2. Split bits	Divide 24 bits into four 6-bit groups.
3. Map chars	Map each 6-bit value (0–63) to a Base64 character.
4. Pad	Add = padding if the input is not divisible by 3.
Result	Output is approximately 33% larger than the original binary input.

Standard vs URL-Safe Base64

Feature	Standard	URL-Safe
Character 62	+	-
Character 63	/	_
Safe in URLs	No — needs encoding	Yes — no encoding needed
Safe in filenames	Not universally	Yes
Use case	Email, general data	URLs, JWT, filenames

Base64 Size Overhead

Formula: Output size = ⌈Input bytes / 3⌉ × 4

1 KB input → approximately 1.33 KB Base64 output
100 KB image → approximately 133 KB Base64 output
1 MB file → approximately 1.33 MB Base64 output

Recommendation: Only embed files under about 10 KB as Data URIs — larger files can significantly increase page weight.

When to Use Base64

Small inline images: icons and logos under 5 KB.
JSON APIs: transmit binary files through text-only endpoints.
JWT tokens: Base64url encodes header and payload.
HTTP Basic Auth: username:password encoded as Base64.
Email attachments: MIME uses Base64 for binary attachments.
CSS sprites: embed small icons directly in stylesheets.

Base64 is NOT Encryption

Base64 provides zero security. Anyone can decode Base64 instantly. It is an encoding scheme, not protection. If you need confidentiality, use appropriate encryption first, then optionally Base64 encode the encrypted output for transmission.

💡 Pro Tips for Base64 Encoding

Use Data URIs only for small files: larger embedded files increase HTML/CSS size.
Always use URL-safe mode for JWTs: JWT uses Base64url.
Enable MIME line breaks for email: RFC 2045 specifies lines no longer than 76 characters for MIME Base64.
Decode Base64 images directly: paste image Base64 in Decode mode to preview supported images.
Use the HTML export for quick embedding: Copy as HTML gives a ready-to-paste image tag.
Check the size comparison panel: compare original and encoded sizes before choosing Data URIs.
Drag and drop for fastest workflow: drop a file directly onto the tool to encode it locally.

Base64 Encoder & Decoder

Powerful Base64 Features

Instant Conversion

Any File Type

URL-Safe Mode

Data URI Support

100% Private

Multiple Export Formats

Common Use Cases for Base64

Embed Images in HTML

CSS Background Images

Email Attachments

API Data Transfer

Database Storage

Authentication Tokens

Base64 Character Set

Base64 Encoding — Complete Developer Guide

What is Base64 Encoding?

How Base64 Works

Standard vs URL-Safe Base64

Base64 Size Overhead

When to Use Base64

Base64 is NOT Encryption

💡 Pro Tips for Base64 Encoding

Frequently Asked Questions

Related Developer Tools

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Value	Char	Value	Char	Value	Char	Value	Char
0	A	16	Q	32	g	48	w
1	B	17	R	33	h	49	x
2	C	18	S	34	i	50	y
3	D	19	T	35	j	51	z
4	E	20	U	36	k	52	0
5	F	21	V	37	l	53	1
6	G	22	W	38	m	54	2
7	H	23	X	39	n	55	3
8	I	24	Y	40	o	56	4
9	J	25	Z	41	p	57	5
10	K	26	a	42	q	58	6
11	L	27	b	43	r	59	7
12	M	28	c	44	s	60	8
13	N	29	d	45	t	61	9
14	O	30	e	46	u	62	+
15	P	31	f	47	v	63	/

Value	Char	Value	Char	Value	Char	Value	Char
0	A	16	Q	32	g	48	w
1	B	17	R	33	h	49	x
2	C	18	S	34	i	50	y
3	D	19	T	35	j	51	z
4	E	20	U	36	k	52	0
5	F	21	V	37	l	53	1
6	G	22	W	38	m	54	2
7	H	23	X	39	n	55	3
8	I	24	Y	40	o	56	4
9	J	25	Z	41	p	57	5
10	K	26	a	42	q	58	6
11	L	27	b	43	r	59	7
12	M	28	c	44	s	60	8
13	N	29	d	45	t	61	9
14	O	30	e	46	u	62	+
15	P	31	f	47	v	63	/

Base64 Encoder & Decoder

Powerful Base64 Features

Instant Conversion

Any File Type

URL-Safe Mode

Data URI Support

100% Private

Multiple Export Formats

Common Use Cases for Base64

Embed Images in HTML

CSS Background Images

Email Attachments

API Data Transfer

Database Storage

Authentication Tokens

Base64 Character Set

Base64 Encoding — Complete Developer Guide

What is Base64 Encoding?

How Base64 Works

Standard vs URL-Safe Base64

Base64 Size Overhead

When to Use Base64

Base64 is NOT Encryption

💡 Pro Tips for Base64 Encoding

Frequently Asked Questions

What is Base64 encoding?

Is Base64 encryption?

Why use Base64 encoding?

Why does Base64 increase file size?

What is URL-safe Base64?

What is a Data URI?

What file types can be converted to Base64?

Is my data safe using this tool?

What is the maximum file size supported?

Can I decode Base64 images and download them?

Related Developer Tools

QR Code Generator

Password Generator

JSON Formatter

Hash Generator

Value	Char	Value	Char	Value	Char	Value	Char
0	A	16	Q	32	g	48	w
1	B	17	R	33	h	49	x
2	C	18	S	34	i	50	y
3	D	19	T	35	j	51	z
4	E	20	U	36	k	52	0
5	F	21	V	37	l	53	1
6	G	22	W	38	m	54	2
7	H	23	X	39	n	55	3
8	I	24	Y	40	o	56	4
9	J	25	Z	41	p	57	5
10	K	26	a	42	q	58	6
11	L	27	b	43	r	59	7
12	M	28	c	44	s	60	8
13	N	29	d	45	t	61	9
14	O	30	e	46	u	62	+
15	P	31	f	47	v	63	/