diff --git a/src/base64.ts b/src/base64.ts
index 62939fd..7263abc 100644
--- a/src/base64.ts
+++ b/src/base64.ts
@@ -7,7 +7,7 @@
 * const restored = base64Decode(converted);
 * ```
 */
-export function base64Encode(data:Uint8Array){
+export function base64Encode(data:Uint8Array):string{
     return btoa([...data].map(n => String.fromCharCode(n)).join(""));
 }
 
@@ -20,6 +20,6 @@ export function base64Encode(data:Uint8Array){
 * const restored = base64Decode(converted);
 * ```
 */
-export function base64Decode(data:string){
+export function base64Decode(data:string):Uint8Array{
     return new Uint8Array([...atob(data)].map(s => s.charCodeAt(0)));
 }
\ No newline at end of file
diff --git a/src/crypto.ts b/src/crypto.ts
index ec8b216..20b3f0d 100644
--- a/src/crypto.ts
+++ b/src/crypto.ts
@@ -50,7 +50,7 @@ async function deriveSecretKey({publicKey, privateKey}:PortableCryptoKeyPair){
 * const uuid = cryptoUuid();
 * ```
 */
-export function cryptoUuid(){
+export function cryptoUuid():string{
     return crypto.randomUUID();
 }
 
@@ -61,7 +61,7 @@ export function cryptoUuid(){
 * const random = cryptoRandom(16);
 * ```
 */
-export function cryptoRandom(n:number){
+export function cryptoRandom(n:number):Uint8Array{
     return crypto.getRandomValues(new Uint8Array(n));
 }
 
@@ -73,7 +73,7 @@ export function cryptoRandom(n:number){
 * const hash = await cryptoHash(256, bin);
 * ```
 */
-export async function cryptoHash(bit:256|384|512, data:Uint8Array){
+export async function cryptoHash(bit:256|384|512, data:Uint8Array):Promise<Uint8Array>{
     return new Uint8Array(await crypto.subtle.digest(`SHA-${bit}`, data));
 }
 
@@ -115,7 +115,7 @@ export async function cryptoGenerateKey(isECDH:boolean):Promise<PortableCryptoKe
 * }, converted);
 * ```
 */
-export async function cryptoEncrypt({publicKey, privateKey}:PortableCryptoKeyPair, data:Uint8Array){
+export async function cryptoEncrypt({publicKey, privateKey}:PortableCryptoKeyPair, data:Uint8Array):Promise<Uint8Array>{
     const gcm = aesGcmConfig(cryptoRandom(sizeIv));
     const output = new Uint8Array((gcm.tagLength ?? 0 / 8) + gcm.iv.byteLength + data.byteLength);
     output.set(<Uint8Array>gcm.iv, 0);
@@ -143,7 +143,7 @@ export async function cryptoEncrypt({publicKey, privateKey}:PortableCryptoKeyPai
 * }, converted);
 * ```
 */
-export async function cryptoDecrypt({publicKey, privateKey}:PortableCryptoKeyPair, data:Uint8Array){
+export async function cryptoDecrypt({publicKey, privateKey}:PortableCryptoKeyPair, data:Uint8Array):Promise<Uint8Array>{
     const gcm = aesGcmConfig(data.subarray(0, sizeIv));
 
     return new Uint8Array(await crypto.subtle.decrypt(gcm, await deriveSecretKey({publicKey, privateKey}), data.subarray(gcm.iv.byteLength)));
@@ -159,7 +159,7 @@ export async function cryptoDecrypt({publicKey, privateKey}:PortableCryptoKeyPai
 * const verified = await cryptoVerify(key.publicKey, signature, bin);
 * ```
 */
-export async function cryptoSign(privateKey:PortableCryptoKey, data:Uint8Array){
+export async function cryptoSign(privateKey:PortableCryptoKey, data:Uint8Array):Promise<Uint8Array>{
     return new Uint8Array(await crypto.subtle.sign(dsaHash, await crypto.subtle.importKey("pkcs8", privateKey, dsaKey, false, ["sign"]), data));
 }
 
@@ -173,6 +173,6 @@ export async function cryptoSign(privateKey:PortableCryptoKey, data:Uint8Array){
 * const verified = await cryptoVerify(key.publicKey, signature, bin);
 * ```
 */
-export async function cryptoVerify(publicKey:PortableCryptoKey, signature:Uint8Array, data:Uint8Array){
+export async function cryptoVerify(publicKey:PortableCryptoKey, signature:Uint8Array, data:Uint8Array):Promise<boolean>{
     return await crypto.subtle.verify(dsaHash, await crypto.subtle.importKey("spki", publicKey, dsaKey, false, ["verify"]), signature, data);
 }
\ No newline at end of file
diff --git a/src/deflate.ts b/src/deflate.ts
index 41d4d9f..75f7894 100644
--- a/src/deflate.ts
+++ b/src/deflate.ts
@@ -12,7 +12,7 @@ async function streamConvert(data:Uint8Array, ts:TransformStream<Uint8Array, Uin
 * const restored = await deflateDecode(converted);
 * ```
 */
-export async function deflateEncode(data:Uint8Array){
+export async function deflateEncode(data:Uint8Array):Promise<Uint8Array>{
     return await streamConvert(data, new CompressionStream("deflate-raw"));
 }
 
@@ -26,6 +26,6 @@ export async function deflateEncode(data:Uint8Array){
 * const restored = await deflateDecode(converted);
 * ```
 */
-export async function deflateDecode(data:Uint8Array){
+export async function deflateDecode(data:Uint8Array):Promise<Uint8Array>{
     return await streamConvert(data, new DecompressionStream("deflate-raw"));
 }
\ No newline at end of file
diff --git a/src/fetch.ts b/src/fetch.ts
index bb70cc3..a831001 100644
--- a/src/fetch.ts
+++ b/src/fetch.ts
@@ -15,7 +15,7 @@ export interface FetchInit extends Omit<RequestInit, "window">{
 /**
 * Map of fetch response type and string specify them.
 */
-export interface FetchResponseType{
+export interface ResponseType{
     "text": string;
     "json": JsonStruct;
     "form": FormData;
@@ -35,7 +35,7 @@ export interface FetchResponseType{
 * const response = await fetchExtend("./asset", "byte");
 * ```
 */
-export async function fetchExtend<T extends keyof FetchResponseType>(path:string, type:T, option?:FetchInit){
+export async function fetchExtend<T extends keyof ResponseType>(path:string, type:T, option?:FetchInit):Promise<ResponseType[T]>{
     const {origin, pathname} = /^http(s|):\/\//i.test(path) ? new URL(path) : new URL(path, location.href);
     const query = new URLSearchParams(option?.query).toString();
 
@@ -56,16 +56,16 @@ export async function fetchExtend<T extends keyof FetchResponseType>(path:string
     });
 
     switch(type){
-        case "text": return <FetchResponseType[T]>await response.text();
-        case "json": return <FetchResponseType[T]>await response.json();
-        case "form": return <FetchResponseType[T]>await response.formData();
-        case "byte": return <FetchResponseType[T]>new Uint8Array(await response.arrayBuffer());
-        case "buffer": return <FetchResponseType[T]>await response.arrayBuffer();
-        case "blob": return <FetchResponseType[T]>await response.blob();
-        case "ok": return <FetchResponseType[T]>response.ok;
-        case "code": return <FetchResponseType[T]>response.status;
-        case "header": return <FetchResponseType[T]>response.headers;
-        case "response": return <FetchResponseType[T]>response;
+        case "text": return <ResponseType[T]>await response.text();
+        case "json": return <ResponseType[T]>await response.json();
+        case "form": return <ResponseType[T]>await response.formData();
+        case "byte": return <ResponseType[T]>new Uint8Array(await response.arrayBuffer());
+        case "buffer": return <ResponseType[T]>await response.arrayBuffer();
+        case "blob": return <ResponseType[T]>await response.blob();
+        case "ok": return <ResponseType[T]>response.ok;
+        case "code": return <ResponseType[T]>response.status;
+        case "header": return <ResponseType[T]>response.headers;
+        case "response": return <ResponseType[T]>response;
         default: throw new Error();
     }
 }
\ No newline at end of file
diff --git a/src/minipack.ts b/src/minipack.ts
index 9883d57..9282676 100644
--- a/src/minipack.ts
+++ b/src/minipack.ts
@@ -21,7 +21,7 @@ export type FileInit = [string, Uint8Array];
 * const restored = minipackDecode(converted);
 * ```
 */
-export function minipackEncode(files:FileInit[]){
+export function minipackEncode(files:FileInit[]):Uint8Array{
     const archive = new Uint8Array(files.reduce((a, [k, v]) => a + sizeName + sizeBody + utfEncode(k).byteLength + v.byteLength, 0));
 
     let i = 0;
@@ -59,7 +59,7 @@ export function minipackEncode(files:FileInit[]){
 * const restored = minipackDecode(converted);
 * ```
 */
-export function minipackDecode(archive:Uint8Array){
+export function minipackDecode(archive:Uint8Array):FileInit[]{
     const files:FileInit[] = [];
 
     for(let i = 0; i < archive.byteLength; false){
diff --git a/src/path.deno.ts b/src/path.deno.ts
index fc2f6f6..7d7cc73 100644
--- a/src/path.deno.ts
+++ b/src/path.deno.ts
@@ -9,7 +9,7 @@ import {isWin} from "./platform.deno.ts";
 * const path = slashUnix("C:\\file");
 * ```
 */
-export function slashUnix(path:string){
+export function slashUnix(path:string):string{
     return path.replaceAll("\\", "/");
 }
 
@@ -21,7 +21,7 @@ export function slashUnix(path:string){
 * const path = slashWin("C:/file");
 * ```
 */
-export function slashWin(path:string){
+export function slashWin(path:string):string{
     return path.replaceAll("/", "\\");
 }
 
@@ -33,7 +33,7 @@ export function slashWin(path:string){
 * const path = tmpPath();
 * ```
 */
-export function tmpPath(){
+export function tmpPath():string{
     return isWin() ? "C:/Windows/Temp" : "/tmp";
 }
 
@@ -45,7 +45,7 @@ export function tmpPath(){
 * const path = dataPath();
 * ```
 */
-export function dataPath(){
+export function dataPath():string{
     return isWin() ? "C:/ProgramData" : "/var";
 }
 
@@ -57,7 +57,7 @@ export function dataPath(){
 * const path = homePath();
 * ```
 */
-export function homePath(){
+export function homePath():string{
     const {HOME, USERPROFILE} = Deno.env.toObject();
 
     return isWin() ? slashUnix(USERPROFILE) : HOME;
@@ -70,7 +70,7 @@ export function homePath(){
 * const path = mainPath();
 * ```
 */
-export function mainPath(){
+export function mainPath():string{
     const path = fromFileUrl(dirname(Deno.mainModule));
 
     return isWin() ? slashUnix(path) : path;
diff --git a/src/platform.deno.ts b/src/platform.deno.ts
index 2072783..90e12d2 100644
--- a/src/platform.deno.ts
+++ b/src/platform.deno.ts
@@ -5,6 +5,6 @@
 * const runOnWin = isWin();
 * ```
 */
-export function isWin(){
+export function isWin():boolean{
     return Deno.build.os === "windows";
 }
\ No newline at end of file
diff --git a/src/process.deno.ts b/src/process.deno.ts
index 6b3bd86..3d09f01 100644
--- a/src/process.deno.ts
+++ b/src/process.deno.ts
@@ -5,7 +5,7 @@
 * const success = executeCommand(["echo", "foobar"]);
 * ```
 */
-export async function runCommand(...commands:string[]){
+export async function runCommand(...commands:string[]):Promise<boolean>{
     const {success} = await new Deno.Command(commands.shift() ?? "", {
         args: commands,
         stdin: "null",
diff --git a/src/text.ts b/src/text.ts
index b70ec16..811e2b6 100644
--- a/src/text.ts
+++ b/src/text.ts
@@ -7,7 +7,7 @@
 * const restored = utfDecode(converted);
 * ```
 */
-export function utfEncode(data:string){
+export function utfEncode(data:string):Uint8Array{
     return new TextEncoder().encode(data);
 }
 
@@ -20,7 +20,7 @@ export function utfEncode(data:string){
 * const restored = utfDecode(converted);
 * ```
 */
-export function utfDecode(data:Uint8Array){
+export function utfDecode(data:Uint8Array):string{
     return new TextDecoder().decode(data);
 }
 
@@ -33,7 +33,7 @@ export function utfDecode(data:Uint8Array){
 * const restored = hexDecode(converted);
 * ```
 */
-export function hexEncode(data:Uint8Array){
+export function hexEncode(data:Uint8Array):string{
     return [...data].map(n => n.toString(16).toUpperCase().padStart(2, "0")).join("");
 }
 
@@ -46,7 +46,7 @@ export function hexEncode(data:Uint8Array){
 * const restored = hexDecode(converted);
 * ```
 */
-export function hexDecode(data:string){
+export function hexDecode(data:string):Uint8Array{
     return new Uint8Array(data.match(/[0-9a-fA-F]{2}/g)?.map(s => parseInt(s, 16)) ?? []);
 }
 
@@ -58,7 +58,7 @@ export function hexDecode(data:string){
 * const formated = trimExtend(text);
 * ```
 */
-export function trimExtend(data:string){
+export function trimExtend(data:string):string{
     return data.trim().replace(/\r/g, "").replace(/\t/g, " ").replace(/ +/g, " ").replace(/ +$/mg, "");
 }
 
@@ -71,6 +71,6 @@ export function trimExtend(data:string){
 * const characters = accurateSegment(text);
 * ```
 */
-export function accurateSegment(data:string){
+export function accurateSegment(data:string):string[]{
     return [...new Intl.Segmenter().segment(data)].map(({segment}) => segment);
 }
\ No newline at end of file
diff --git a/src/time.ts b/src/time.ts
index cbe4c59..4b8a5a0 100644
--- a/src/time.ts
+++ b/src/time.ts
@@ -7,7 +7,7 @@
 * const date = unixtimeDecode(time);
 * ```
 */
-export function unixtimeEncode(date?:Date){
+export function unixtimeEncode(date?:Date):number{
     return Math.floor((date ?? new Date()).getTime() / 1000);
 }
 
@@ -20,7 +20,7 @@ export function unixtimeEncode(date?:Date){
 * const date = unixtimeDecode(time);
 * ```
 */
-export function unixtimeDecode(time:number){
+export function unixtimeDecode(time:number):Date{
     return new Date(time * 1000);
 }
 
@@ -31,7 +31,7 @@ export function unixtimeDecode(time:number){
 * const time = unixtimeParse("2023-05-18T08:31:32.292Z");
 * ```
 */
-export function unixtimeParse(ds:string){
+export function unixtimeParse(ds:string):number{
     const [y, mo, d, h, mi, s] = ds.split(/[/ :TZ_.-]/i).map(s => Number(s));
 
     return unixtimeEncode(new Date(y, (mo ?? 1) - 1, d ?? 1, h ?? 0, mi ?? 0, s ?? 0));