diff --git a/.config/docker_example.yml b/.config/docker_example.yml
index 89e6925408..940b095fe2 100644
--- a/.config/docker_example.yml
+++ b/.config/docker_example.yml
@@ -114,6 +114,7 @@ redis:
 
 # Available methods:
 # aid ... Short, Millisecond accuracy
+# aidx ... Millisecond accuracy
 # meid ... Similar to ObjectID, Millisecond accuracy
 # ulid ... Millisecond accuracy
 # objectid ... This is left for backward compatibility
@@ -121,7 +122,7 @@ redis:
 # ONCE YOU HAVE STARTED THE INSTANCE, DO NOT CHANGE THE
 # ID SETTINGS AFTER THAT!
 
-id: 'aid'
+id: 'aidx'
 
 #   ┌─────────────────────┐
 #───┘ Other configuration └─────────────────────────────────────
diff --git a/.config/example.yml b/.config/example.yml
index cca44ce88c..086a6ca8fc 100644
--- a/.config/example.yml
+++ b/.config/example.yml
@@ -125,6 +125,7 @@ redis:
 
 # Available methods:
 # aid ... Short, Millisecond accuracy
+# aidx ... Millisecond accuracy
 # meid ... Similar to ObjectID, Millisecond accuracy
 # ulid ... Millisecond accuracy
 # objectid ... This is left for backward compatibility
@@ -132,7 +133,7 @@ redis:
 # ONCE YOU HAVE STARTED THE INSTANCE, DO NOT CHANGE THE
 # ID SETTINGS AFTER THAT!
 
-id: 'aid'
+id: 'aidx'
 
 #   ┌─────────────────────┐
 #───┘ Other configuration └─────────────────────────────────────
diff --git a/.devcontainer/devcontainer.yml b/.devcontainer/devcontainer.yml
index 5cfb6174ca..5dcd41599a 100644
--- a/.devcontainer/devcontainer.yml
+++ b/.devcontainer/devcontainer.yml
@@ -114,6 +114,7 @@ redis:
 
 # Available methods:
 # aid ... Short, Millisecond accuracy
+# aidx ... Millisecond accuracy
 # meid ... Similar to ObjectID, Millisecond accuracy
 # ulid ... Millisecond accuracy
 # objectid ... This is left for backward compatibility
@@ -121,7 +122,7 @@ redis:
 # ONCE YOU HAVE STARTED THE INSTANCE, DO NOT CHANGE THE
 # ID SETTINGS AFTER THAT!
 
-id: 'aid'
+id: 'aidx'
 
 #   ┌─────────────────────┐
 #───┘ Other configuration └─────────────────────────────────────
diff --git a/.github/misskey/test.yml b/.github/misskey/test.yml
index f43f74be14..7a4aa4ae6c 100644
--- a/.github/misskey/test.yml
+++ b/.github/misskey/test.yml
@@ -12,4 +12,4 @@ db:
 redis:
   host: 127.0.0.1
   port: 56312
-id: aid
+id: aidx
diff --git a/chart/files/default.yml b/chart/files/default.yml
index e62032abfd..90b574b99f 100644
--- a/chart/files/default.yml
+++ b/chart/files/default.yml
@@ -135,6 +135,7 @@ redis:
 
 # Available methods:
 # aid ... Short, Millisecond accuracy
+# aidx ... Millisecond accuracy
 # meid ... Similar to ObjectID, Millisecond accuracy
 # ulid ... Millisecond accuracy
 # objectid ... This is left for backward compatibility
@@ -142,7 +143,7 @@ redis:
 # ONCE YOU HAVE STARTED THE INSTANCE, DO NOT CHANGE THE
 # ID SETTINGS AFTER THAT!
 
-id: "aid"
+id: "aidx"
 #   ┌─────────────────────┐
 #───┘ Other configuration └─────────────────────────────────────
 
diff --git a/packages/backend/package.json b/packages/backend/package.json
index 4768ffd0ed..526d7d4678 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -120,6 +120,7 @@
 		"mime-types": "2.1.35",
 		"misskey-js": "workspace:*",
 		"ms": "3.0.0-canary.1",
+		"nanoid": "4.0.2",
 		"nested-property": "4.0.0",
 		"node-fetch": "3.3.2",
 		"nodemailer": "6.9.4",
diff --git a/packages/backend/src/core/IdService.ts b/packages/backend/src/core/IdService.ts
index 186fd36b42..06c58ad8a1 100644
--- a/packages/backend/src/core/IdService.ts
+++ b/packages/backend/src/core/IdService.ts
@@ -8,6 +8,7 @@ import { ulid } from 'ulid';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
 import { genAid, parseAid } from '@/misc/id/aid.js';
+import { genAidx, parseAidx } from '@/misc/id/aidx.js';
 import { genMeid, parseMeid } from '@/misc/id/meid.js';
 import { genMeidg, parseMeidg } from '@/misc/id/meidg.js';
 import { genObjectId, parseObjectId } from '@/misc/id/object-id.js';
@@ -31,6 +32,7 @@ export class IdService {
 
 		switch (this.method) {
 			case 'aid': return genAid(date);
+			case 'aidx': return genAidx(date);
 			case 'meid': return genMeid(date);
 			case 'meidg': return genMeidg(date);
 			case 'ulid': return ulid(date.getTime());
@@ -43,6 +45,7 @@ export class IdService {
 	public parse(id: string): { date: Date; } {
 		switch (this.method) {
 			case 'aid': return parseAid(id);
+			case 'aidx': return parseAidx(id);
 			case 'objectid': return parseObjectId(id);
 			case 'meid': return parseMeid(id);
 			case 'meidg': return parseMeidg(id);
diff --git a/packages/backend/src/misc/id/aidx.ts b/packages/backend/src/misc/id/aidx.ts
new file mode 100644
index 0000000000..5b031ea4c0
--- /dev/null
+++ b/packages/backend/src/misc/id/aidx.ts
@@ -0,0 +1,44 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+// AIDX
+// 長さ8の[2000年1月1日からの経過ミリ秒をbase36でエンコードしたもの] + 長さ4の[個体ID] + 長さ4の[カウンタ]
+// (c) mei23
+// https://misskey.m544.net/notes/71899acdcc9859ec5708ac24
+
+import { customAlphabet } from 'nanoid';
+
+export const aidxRegExp = /^[0-9a-z]{16}$/;
+
+const TIME2000 = 946684800000;
+const TIME_LENGTH = 8;
+const NODE_LENGTH = 4;
+const NOISE_LENGTH = 4;
+
+const nodeId = customAlphabet('0123456789abcdefghijklmnopqrstuvwxyz', NODE_LENGTH)();
+let counter = 0;
+
+function getTime(time: number): string {
+	time = time - TIME2000;
+	if (time < 0) time = 0;
+
+	return time.toString(36).padStart(TIME_LENGTH, '0').slice(-TIME_LENGTH);
+}
+
+function getNoise(): string {
+	return counter.toString(36).padStart(NOISE_LENGTH, '0').slice(-NOISE_LENGTH);
+}
+
+export function genAidx(date: Date): string {
+	const t = date.getTime();
+	if (isNaN(t)) throw new Error('Failed to create AIDX: Invalid Date');
+	counter++;
+	return getTime(t) + nodeId + getNoise();
+}
+
+export function parseAidx(id: string): { date: Date; } {
+	const time = parseInt(id.slice(0, TIME_LENGTH), 36) + TIME2000;
+	return { date: new Date(time) };
+}
diff --git a/packages/backend/test/unit/AnnouncementService.ts b/packages/backend/test/unit/AnnouncementService.ts
index f09ae3e2f4..d11808a4d8 100644
--- a/packages/backend/test/unit/AnnouncementService.ts
+++ b/packages/backend/test/unit/AnnouncementService.ts
@@ -12,7 +12,7 @@ import { GlobalModule } from '@/GlobalModule.js';
 import { AnnouncementService } from '@/core/AnnouncementService.js';
 import type { MiAnnouncement, AnnouncementsRepository, AnnouncementReadsRepository, UsersRepository, MiUser } from '@/models/index.js';
 import { DI } from '@/di-symbols.js';
-import { genAid } from '@/misc/id/aid.js';
+import { genAidx } from '@/misc/id/aidx.js';
 import { CacheService } from '@/core/CacheService.js';
 import { IdService } from '@/core/IdService.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
@@ -33,7 +33,7 @@ describe('AnnouncementService', () => {
 	function createUser(data: Partial<MiUser> = {}) {
 		const un = secureRndstr(16);
 		return usersRepository.insert({
-			id: genAid(new Date()),
+			id: genAidx(new Date()),
 			createdAt: new Date(),
 			username: un,
 			usernameLower: un,
@@ -44,7 +44,7 @@ describe('AnnouncementService', () => {
 
 	function createAnnouncement(data: Partial<MiAnnouncement> = {}) {
 		return announcementsRepository.insert({
-			id: genAid(new Date()),
+			id: genAidx(new Date()),
 			createdAt: new Date(),
 			updatedAt: null,
 			title: 'Title',
diff --git a/packages/backend/test/unit/RoleService.ts b/packages/backend/test/unit/RoleService.ts
index 32a686c83a..52224acabf 100644
--- a/packages/backend/test/unit/RoleService.ts
+++ b/packages/backend/test/unit/RoleService.ts
@@ -14,7 +14,7 @@ import { RoleService } from '@/core/RoleService.js';
 import type { MiRole, RolesRepository, RoleAssignmentsRepository, UsersRepository, MiUser } from '@/models/index.js';
 import { DI } from '@/di-symbols.js';
 import { MetaService } from '@/core/MetaService.js';
-import { genAid } from '@/misc/id/aid.js';
+import { genAidx } from '@/misc/id/aidx.js';
 import { CacheService } from '@/core/CacheService.js';
 import { IdService } from '@/core/IdService.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
@@ -37,7 +37,7 @@ describe('RoleService', () => {
 	function createUser(data: Partial<MiUser> = {}) {
 		const un = secureRndstr(16);
 		return usersRepository.insert({
-			id: genAid(new Date()),
+			id: genAidx(new Date()),
 			createdAt: new Date(),
 			username: un,
 			usernameLower: un,
@@ -48,7 +48,7 @@ describe('RoleService', () => {
 
 	function createRole(data: Partial<MiRole> = {}) {
 		return rolesRepository.insert({
-			id: genAid(new Date()),
+			id: genAidx(new Date()),
 			createdAt: new Date(),
 			updatedAt: new Date(),
 			lastUsedAt: new Date(),
diff --git a/packages/backend/test/unit/misc/id.ts b/packages/backend/test/unit/misc/id.ts
index 8cc2ea425f..57b4ea9947 100644
--- a/packages/backend/test/unit/misc/id.ts
+++ b/packages/backend/test/unit/misc/id.ts
@@ -6,6 +6,7 @@
 import { ulid } from 'ulid';
 import { describe, test, expect } from '@jest/globals';
 import { aidRegExp, genAid, parseAid } from '@/misc/id/aid.js';
+import { aidxRegExp, genAidx, parseAidx } from '@/misc/id/aidx.js';
 import { genMeid, meidRegExp, parseMeid } from '@/misc/id/meid.js';
 import { genMeidg, meidgRegExp, parseMeidg } from '@/misc/id/meidg.js';
 import { genObjectId, objectIdRegExp, parseObjectId } from '@/misc/id/object-id.js';
@@ -19,6 +20,13 @@ describe('misc:id', () => {
 		expect(parseAid(gotAid).date.getTime()).toBe(date.getTime());
 	});
 
+	test('aidx', () => {
+		const date = new Date();
+		const gotAidx = genAidx(date);
+		expect(gotAidx).toMatch(aidxRegExp);
+		expect(parseAidx(gotAidx).date.getTime()).toBe(date.getTime());
+	});
+
 	test('meid', () => {
 		const date = new Date();
 		const gotMeid = genMeid(date);
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 950fa3e37b..32d9916a37 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -260,6 +260,9 @@ importers:
       ms:
         specifier: 3.0.0-canary.1
         version: 3.0.0-canary.1
+      nanoid:
+        specifier: ^4.0.2
+        version: 4.0.2
       nested-property:
         specifier: 4.0.0
         version: 4.0.0
@@ -6998,7 +7001,7 @@ packages:
       ts-dedent: 2.2.0
       type-fest: 2.19.0
       vue: 3.3.4
-      vue-component-type-helpers: 1.8.8
+      vue-component-type-helpers: 1.8.10
     transitivePeerDependencies:
       - encoding
       - supports-color
@@ -16069,6 +16072,12 @@ packages:
     engines: {node: ^10 || ^12 || ^13.7 || ^14 || >=15.0.1}
     hasBin: true
 
+  /nanoid@4.0.2:
+    resolution: {integrity: sha512-7ZtY5KTCNheRGfEFxnedV5zFiORN1+Y1N6zvPTnHQd8ENUvfaDBeuJDZb2bN/oXwXxu3qkTXDzy57W5vAmDTBw==}
+    engines: {node: ^14 || ^16 || >=18}
+    hasBin: true
+    dev: false
+
   /nanomatch@1.2.13:
     resolution: {integrity: sha512-fpoe2T0RbHwBTBUOftAfBPaDEi06ufaUai0mE6Yn1kacc3SnTErfb/h+X94VXzI64rKFHYImXSvdwGGCmwOqCA==}
     engines: {node: '>=0.10.0'}
@@ -21040,8 +21049,8 @@ packages:
     resolution: {integrity: sha512-Dhxzh5HZuiHQhbvTW9AMetFfBHDMYpo23Uo9btPXgdYP+3T5S+p+jgNy7spra+veYhBP2dCSgxR/i2Y02h5/6w==}
     engines: {node: '>=0.10.0'}
 
-  /vue-component-type-helpers@1.8.8:
-    resolution: {integrity: sha512-Ohv9HQY92nSbpReC6WhY0X4YkOszHzwUHaaN/lev5tHQLM1AEw+LrLeB2bIGIyKGDU7ZVrncXcv/oBny4rjbYg==}
+  /vue-component-type-helpers@1.8.10:
+    resolution: {integrity: sha512-FJtmfw2Gn6eQ8kAVNEhw9nYIzWmVQJjdyQRtJXZ7tgXh/FoZhQnZ2KyxR+NuF9U4iZLBvSspeetIpnP9yxxyMw==}
     dev: true
 
   /vue-docgen-api@4.64.1(vue@3.3.4):