diff --git a/packages/backend/src/migration/1701118152149-increase-host-char-limit.ts b/packages/backend/src/migration/1701118152149-increase-host-char-limit.ts
new file mode 100644
index 000000000..5703a4c13
--- /dev/null
+++ b/packages/backend/src/migration/1701118152149-increase-host-char-limit.ts
@@ -0,0 +1,47 @@
+import { MigrationInterface, QueryRunner } from "typeorm"
+
+export class IncreaseHostCharLimit1701118152149 implements MigrationInterface {
+    name = 'IncreaseHostCharLimit1701118152149';
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`ALTER TABLE "drive_file" ALTER COLUMN "userHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "user" ALTER COLUMN "host" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "user_profile" ALTER COLUMN "userHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "user_publickey" ALTER COLUMN "keyId" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "emoji" ALTER COLUMN "host" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "userHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "replyUserHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "renoteUserHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "host" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "iconUrl" TYPE character varying(4096)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "faviconUrl" TYPE character varying(4096)`);
+        await queryRunner.query(`ALTER TABLE "poll" ALTER COLUMN "userHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "abuse_user_report" ALTER COLUMN "targetUserHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "abuse_user_report" ALTER COLUMN "reporterHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "following" ALTER COLUMN "followeeHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "following" ALTER COLUMN "followerHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "follow_request" ALTER COLUMN "followeeHost" TYPE character varying(512)`);
+        await queryRunner.query(`ALTER TABLE "follow_request" ALTER COLUMN "followerHost" TYPE character varying(512)`);
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`ALTER TABLE "drive_file" ALTER COLUMN "userHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "user" ALTER COLUMN "host" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "user_profile" ALTER COLUMN "userHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "user_publickey" ALTER COLUMN "keyId" TYPE character varying(256)`);
+        await queryRunner.query(`ALTER TABLE "emoji" ALTER COLUMN "host" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "userHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "replyUserHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "renoteUserHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "host" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "iconUrl" TYPE character varying(256)`);
+        await queryRunner.query(`ALTER TABLE "instance" ALTER COLUMN "faviconUrl" TYPE character varying(256)`);
+        await queryRunner.query(`ALTER TABLE "poll" ALTER COLUMN "userHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "abuse_user_report" ALTER COLUMN "targetUserHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "abuse_user_report" ALTER COLUMN "reporterHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "following" ALTER COLUMN "followeeHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "following" ALTER COLUMN "followerHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "follow_request" ALTER COLUMN "followeeHost" TYPE character varying(128)`);
+        await queryRunner.query(`ALTER TABLE "follow_request" ALTER COLUMN "followerHost" TYPE character varying(128)`);
+    }
+}
diff --git a/packages/backend/src/models/entities/abuse-user-report.ts b/packages/backend/src/models/entities/abuse-user-report.ts
index be183548d..cb4d55851 100644
--- a/packages/backend/src/models/entities/abuse-user-report.ts
+++ b/packages/backend/src/models/entities/abuse-user-report.ts
@@ -71,7 +71,7 @@ export class AbuseUserReport {
 	//#region Denormalized fields
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
@@ -79,7 +79,7 @@ export class AbuseUserReport {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/drive-file.ts b/packages/backend/src/models/entities/drive-file.ts
index f65dad110..54f5a8ca2 100644
--- a/packages/backend/src/models/entities/drive-file.ts
+++ b/packages/backend/src/models/entities/drive-file.ts
@@ -39,7 +39,7 @@ export class DriveFile {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "The host of owner. It will be null if the user in local.",
 	})
diff --git a/packages/backend/src/models/entities/emoji.ts b/packages/backend/src/models/entities/emoji.ts
index 727ba2f10..87b525dc5 100644
--- a/packages/backend/src/models/entities/emoji.ts
+++ b/packages/backend/src/models/entities/emoji.ts
@@ -20,7 +20,7 @@ export class Emoji {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 	})
 	public host: string | null;
diff --git a/packages/backend/src/models/entities/follow-request.ts b/packages/backend/src/models/entities/follow-request.ts
index 281eab917..a1c747d91 100644
--- a/packages/backend/src/models/entities/follow-request.ts
+++ b/packages/backend/src/models/entities/follow-request.ts
@@ -55,7 +55,7 @@ export class FollowRequest {
 
 	//#region Denormalized fields
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
@@ -76,7 +76,7 @@ export class FollowRequest {
 	public followerSharedInbox: string | null;
 
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/following.ts b/packages/backend/src/models/entities/following.ts
index fafcf8885..ea8f32565 100644
--- a/packages/backend/src/models/entities/following.ts
+++ b/packages/backend/src/models/entities/following.ts
@@ -50,7 +50,7 @@ export class Following {
 	//#region Denormalized fields
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
@@ -72,7 +72,7 @@ export class Following {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/instance.ts b/packages/backend/src/models/entities/instance.ts
index 7e0b08583..7b7701d07 100644
--- a/packages/backend/src/models/entities/instance.ts
+++ b/packages/backend/src/models/entities/instance.ts
@@ -20,7 +20,7 @@ export class Instance {
 	 */
 	@Index({ unique: true })
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		comment: "The host of the Instance.",
 	})
 	public host: string;
@@ -149,13 +149,13 @@ export class Instance {
 	public maintainerEmail: string | null;
 
 	@Column("varchar", {
-		length: 256,
+		length: 4096,
 		nullable: true,
 	})
 	public iconUrl: string | null;
 
 	@Column("varchar", {
-		length: 256,
+		length: 4096,
 		nullable: true,
 	})
 	public faviconUrl: string | null;
diff --git a/packages/backend/src/models/entities/note.ts b/packages/backend/src/models/entities/note.ts
index a99cb8033..886e6538f 100644
--- a/packages/backend/src/models/entities/note.ts
+++ b/packages/backend/src/models/entities/note.ts
@@ -221,7 +221,7 @@ export class Note {
 	//#region Denormalized fields
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
@@ -235,7 +235,7 @@ export class Note {
 	public replyUserId: User["id"] | null;
 
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
@@ -249,7 +249,7 @@ export class Note {
 	public renoteUserId: User["id"] | null;
 
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/poll.ts b/packages/backend/src/models/entities/poll.ts
index 405cca222..c117d4e73 100644
--- a/packages/backend/src/models/entities/poll.ts
+++ b/packages/backend/src/models/entities/poll.ts
@@ -58,7 +58,7 @@ export class Poll {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/user-profile.ts b/packages/backend/src/models/entities/user-profile.ts
index e800c9a6c..f53360862 100644
--- a/packages/backend/src/models/entities/user-profile.ts
+++ b/packages/backend/src/models/entities/user-profile.ts
@@ -242,7 +242,7 @@ export class UserProfile {
 	//#region Denormalized fields
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment: "[Denormalized]",
 	})
diff --git a/packages/backend/src/models/entities/user-publickey.ts b/packages/backend/src/models/entities/user-publickey.ts
index 83a86b8a3..e39b084d3 100644
--- a/packages/backend/src/models/entities/user-publickey.ts
+++ b/packages/backend/src/models/entities/user-publickey.ts
@@ -22,7 +22,7 @@ export class UserPublickey {
 
 	@Index({ unique: true })
 	@Column("varchar", {
-		length: 256,
+		length: 512,
 	})
 	public keyId: string;
 
diff --git a/packages/backend/src/models/entities/user.ts b/packages/backend/src/models/entities/user.ts
index 4b3bf553f..d7412500e 100644
--- a/packages/backend/src/models/entities/user.ts
+++ b/packages/backend/src/models/entities/user.ts
@@ -229,7 +229,7 @@ export class User {
 
 	@Index()
 	@Column("varchar", {
-		length: 128,
+		length: 512,
 		nullable: true,
 		comment:
 			"The host of the User. It will be null if the origin of the user is local.",