What is Base64 encoding and why is it used?

Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 ASCII printable characters (A-Z, a-z, 0-9, +, /). It is used to safely transmit binary media (images, attachments, keys) across text-based protocols like HTTP, HTML, and email (MIME).

How does URL-Safe Base64 (Base64URL) differ from standard Base64?

Standard Base64 uses `+` and `/`, which have special meanings in URL query strings. URL-Safe Base64 replaces `+` with `-` (hyphen) and `/` with `_` (underscore), and typically omits padding `=` characters.

Why does Base64 encoding increase data size by approximately 33%?

Base64 takes 3 bytes of binary data (24 bits) and splits them into 4 groups of 6 bits, representing each 6-bit group as an ASCII character. This 4:3 ratio increases data size by exactly 33.3%.

How are UTF-8 emojis and special characters safely encoded in Base64?

JavaScript's legacy `btoa()` only accepts Latin1 (8-bit) strings. Our tool first converts UTF-8 strings into `Uint8Array` bytes using the standard `TextEncoder` API before encoding, preventing `CharacterOutOfBounds` errors.

Developer Tools

Base64 Encoder & Decoder

Secure, client-side Base64 converter for text and images. Encode images into ready-to-copy HTML/CSS inline snippets or parse Base64 data back to raw formats instantly.

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Pro TipType natural queries like "encode My API Payload", "decode SGVsbG8=" or paste an image URL to auto-load and convert instantly!

Drag & Drop Image

Supports JPG, PNG, WebP, SVG

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Base64 Character Reference Table

Base64 encoding maps standard binary data into 64 safe, printable ASCII characters. Each character represents exactly 6 bits of data. Use the bright, colorful index mapping reference chart below to visualize the decimal, binary, and ASCII equivalencies:

Index (6-bit Value)	Binary	Character (Base64)	Decimal Equivalent
0	000000	A	65
1	000001	B	66
2	000010	C	67
3	000011	D	68
4	000100	E	69
5	000101	F	70
6	000110	G	71
7	000111	H	72
8	001000	I	73
9	001001	J	74
10	001010	K	75
11	001011	L	76
12	001100	M	77
13	001101	N	78
14	001110	O	79
15	001111	P	80
16	010000	Q	81
17	010001	R	82
18	010010	S	83
19	010011	T	84
20	010100	U	85
21	010101	V	86
22	010110	W	87
23	010111	X	88
24	011000	Y	89
25	011001	Z	90
26	011010	a	97
27	011011	b	98
28	011100	c	99
29	011101	d	100
30	011110	e	101
31	011111	f	102
32	100000	g	103
33	100001	h	104
34	100010	i	105
35	100011	j	106
36	100100	k	107
37	100101	l	108
38	100110	m	109
39	100111	n	110
40	101000	o	111
41	101001	p	112
42	101010	q	113
43	101011	r	114
44	101100	s	115
45	101101	t	116
46	101110	u	117
47	101111	v	118
48	110000	w	119
49	110001	x	120
50	110010	y	121
51	110011	z	122
52	110100	0	48
53	110101	1	49
54	110110	2	50
55	110111	3	51
56	111000	4	52
57	111001	5	53
58	111010	6	54
59	111011	7	55
60	111100	8	56
61	111101	9	57
62	111110	+	43
63	111111	/	47
64	Padding	=	61

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What is Base64?

Base64 is a binary-to-text encoding scheme that translates raw binary data (0s and 1s) into standard ASCII printable characters. By partitioning every 24 bits into four 6-bit chunks, it maps binary payloads securely to a safe 64-character index set.

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Core Features

Our tool runs entirely client-side inside your browser with 100% data privacy. It features instant text conversions, responsive image-to-base64 encoders with pixel dimension readers, standard HTML/CSS snippet wrappers, and automated URL-safe conversions.

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Why Use Base64?

It guarantees safe data transmission over networks that only support raw text formats (like emails, XML feeds, or JSON databases). Inline base64 assets allow you to embed images directly into HTML/CSS files, reducing extra HTTP network requests.