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@std/encoding
Overview Jump to heading
Utilities for encoding and decoding common formats like hex, base64, and varint.
Basic Usage
import { encodeBase64, decodeBase64 } from "@std/encoding";
import { assertEquals } from "@std/assert";
const foobar = new TextEncoder().encode("foobar");
assertEquals(encodeBase64(foobar), "Zm9vYmFy");
assertEquals(decodeBase64("Zm9vYmFy"), foobar);
Various Encoding Formats
import {
encodeHex,
encodeBase32,
encodeBase58,
encodeBase64,
encodeAscii85,
decodeHex,
decodeBase32,
decodeBase58,
decodeBase64,
decodeAscii85,
} from "@std/encoding";
import { assertEquals } from "@std/assert";
// Many different encodings for different character sets
assertEquals(encodeHex("Hello world!"), "48656c6c6f20776f726c6421");
assertEquals(encodeBase32("Hello world!"), "JBSWY3DPEB3W64TMMQQQ====");
assertEquals(encodeBase58("Hello world!"), "2NEpo7TZRhna7vSvL");
assertEquals(encodeBase64("Hello world!"), "SGVsbG8gd29ybGQh");
assertEquals(encodeAscii85("Hello world!"), "87cURD]j7BEbo80");
// Decoding
assertEquals(new TextDecoder().decode(decodeHex("48656c6c6f20776f726c6421")), "Hello world!");
assertEquals(new TextDecoder().decode(decodeBase32("JBSWY3DPEB3W64TMMQQQ====")), "Hello world!");
assertEquals(new TextDecoder().decode(decodeBase58("2NEpo7TZRhna7vSvL")), "Hello world!");
assertEquals(new TextDecoder().decode(decodeBase64("SGVsbG8gd29ybGQh")), "Hello world!");
assertEquals(new TextDecoder().decode(decodeAscii85("87cURD]j7BEbo80")), "Hello world!");
URL-Safe Base64
import { encodeBase64, encodeBase64Url } from "@std/encoding";
import { assertEquals } from "@std/assert";
assertEquals(encodeBase64("ice creams"), "aWNlIGNyZWFtcw=="); // Not url-safe because of `=`
assertEquals(encodeBase64Url("ice creams"), "aWNlIGNyZWFtcw"); // URL-safe!
// Base64Url replaces + with - and / with _
assertEquals(encodeBase64("subjects?"), "c3ViamVjdHM/"); // slash is not URL-safe
assertEquals(encodeBase64Url("subjects?"), "c3ViamVjdHM_"); // _ is URL-safe
Binary Data Encoding
import { encodeHex, encodeBase64 } from "@std/encoding";
import { assertEquals } from "@std/assert";
// Working with binary data
const binaryData = new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF]);
assertEquals(encodeHex(binaryData), "deadbeef");
assertEquals(encodeBase64(binaryData), "3q2+7w==");
Varint Encoding
Learn more from the protobuf Varint encoding docs.
import { encodeVarint, decodeVarint } from "@std/encoding";
import { assertEquals } from "@std/assert";
// Varint encoding support
assertEquals(encodeVarint(9601n), [new Uint8Array([129, 75]), 2]);
// Decode a varint
const bytes = new Uint8Array([129, 75]);
assertEquals(decodeVarint(bytes), [9601n, 2]);
Add to your project Jump to heading
deno add jsr:@std/encoding
See all symbols in @std/encoding on
什么是编码？ Jump to heading
编码是将数据从一种格式转换到另一种格式的过程，通常用于使数据适合传输或存储。常见的编码格式包括 Base64、Hex 和 Varint。
为什么使用 @std/encoding？ Jump to heading
该包提供简单、可靠的函数，用于以多种格式编码和解码数据。你将使用编码来：
- 互操作性：以人类可读/可传输的形式（URL、JSON、命令行、日志）交换二进制数据。
- 安全性：解码助手在输入格式错误时（例如 hex）抛出错误，而不是默默截断。
- 可移植性：跨运行时提供统一的 API。
- 控制性：选择 URL 安全的 Base64 避免 URL 中出现 +、/、=。
示例 Jump to heading
import {
decodeBase64Url,
decodeHex,
encodeBase64Url,
encodeHex,
} from "@std/encoding";
// 字符串 ↔ 字节
const bytes = new TextEncoder().encode("hello");
const text = new TextDecoder().decode(bytes);
// URL 安全的 token
const token = encodeBase64Url(bytes); // aGVsbG8
const roundtrip = new TextDecoder().decode(decodeBase64Url(token));
// Hex 工具
const hex = encodeHex(bytes); // 68656c6c6f
const fromHex = decodeHex(hex);
// 其他支持的编码
import {
decodeAscii85,
decodeBase32,
decodeBase58,
decodeBase64,
encodeAscii85,
encodeBase32,
encodeBase58,
encodeBase64,
} from "@std/encoding";
encodeBase64("Hello world!"); // "SGVsbG8gd29ybGQh"
encodeBase32("Hello world!"); // "JBSWY3DPEB3W64TMMQQQ===="
encodeBase58("Hello world!"); // "2NEpo7TZRhna7vSvL"
encodeAscii85("Hello world!"); // "87cURD]j7BEbo80"
new TextDecoder().decode(decodeBase64("SGVsbG8gd29ybGQh")); // "Hello world!"
// Varint（紧凑型整数编码）
import { decodeVarint, encodeVarint } from "@std/encoding";
const [buf, end] = encodeVarint(9601n);
const [num, next] = decodeVarint(buf);
小贴士 Jump to heading
- 所有编码器/解码器均使用
Uint8Array。使用TextEncoder/TextDecoder进行字符串 ↔ 字节转换。 - token 和查询参数建议使用 Base64URL；标准 Base64 可能包含需要转义的字符。
- Hex 工具默认返回小写字母。
- Varint 紧凑编码整数；不适用于任意二进制负载。