diff --git a/package.json b/package.json
index af8e08d..44517df 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "test:types": "tsc --noEmit --module esnext --skipLibCheck --moduleResolution node ./test/*.test.ts"
   },
   "dependencies": {
+    "detect-indent": "^7.0.1",
     "jsonc-parser": "^3.2.0",
     "mlly": "^1.1.1",
     "pathe": "^1.1.0"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5684292..c6983aa 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -4,6 +4,7 @@ specifiers:
   '@types/node': ^18.13.0
   '@vitest/coverage-c8': ^0.28.5
   changelogen: ^0.4.1
+  detect-indent: ^7.0.1
   eslint: ^8.34.0
   eslint-config-unjs: ^0.1.0
   expect-type: ^0.15.0
@@ -17,6 +18,7 @@ specifiers:
   vitest: ^0.28.5
 
 dependencies:
+  detect-indent: 7.0.1
   jsonc-parser: 3.2.0
   mlly: 1.1.1
   pathe: 1.1.0
@@ -1499,6 +1501,11 @@ packages:
     resolution: {integrity: sha512-lrbCJwD9saUQrqUfXvl6qoM+QN3W7tLV5pAOs+OqOmopCCz/JkE05MHedJR1xfk4IAnZuJXPVuN5+7jNA2ZCiA==}
     dev: true
 
+  /detect-indent/7.0.1:
+    resolution: {integrity: sha512-Mc7QhQ8s+cLrnUfU/Ji94vG/r8M26m8f++vyres4ZoojaRDpZ1eSIh/EpzLNwlWuvzSZ3UbDFspjFvTDXe6e/g==}
+    engines: {node: '>=12.20'}
+    dev: false
+
   /diff/5.1.0:
     resolution: {integrity: sha512-D+mk+qE8VC/PAUrlAU34N+VfXev0ghe5ywmpqrawphmVZc1bEfn56uo9qpyGp1p4xpzOHkSW4ztBd6L7Xx4ACw==}
     engines: {node: '>=0.3.1'}
diff --git a/src/index.ts b/src/index.ts
index 9062a63..9633f3d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,13 @@
 import { promises as fsp } from "node:fs";
 import { dirname, resolve, isAbsolute } from "pathe";
 import { ResolveOptions as _ResolveOptions, resolvePath } from "mlly";
-import { findFile, FindFileOptions, findNearestFile } from "./utils";
+import {
+  findFile,
+  FindFileOptions,
+  findNearestFile,
+  writeJsonFile,
+  WriteOptions,
+} from "./utils";
 import type { PackageJson, TSConfig } from "./types";
 
 export * from "./types";
@@ -42,9 +48,10 @@ export async function readPackageJSON(
 
 export async function writePackageJSON(
   path: string,
-  package_: PackageJson
+  package_: PackageJson,
+  options: WriteOptions = {}
 ): Promise<void> {
-  await fsp.writeFile(path, JSON.stringify(package_, undefined, 2));
+  await writeJsonFile(path, package_, options);
 }
 
 export async function readTSConfig(
@@ -68,9 +75,10 @@ export async function readTSConfig(
 
 export async function writeTSConfig(
   path: string,
-  tsconfig: TSConfig
+  tsconfig: TSConfig,
+  options: WriteOptions = {}
 ): Promise<void> {
-  await fsp.writeFile(path, JSON.stringify(tsconfig, undefined, 2));
+  await writeJsonFile(path, tsconfig, options);
 }
 
 export async function resolvePackageJSON(
diff --git a/src/utils.ts b/src/utils.ts
index 93e989e..bfaaf84 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,5 +1,7 @@
-import { statSync } from "node:fs";
+import { statSync, existsSync } from "node:fs";
+import { readFile, writeFile } from "node:fs/promises";
 import { join, resolve } from "pathe";
+import detectIndent from "detect-indent";
 
 export interface FindFileOptions {
   /**
@@ -30,6 +32,16 @@ export interface FindFileOptions {
 /** @deprecated */
 export type FindNearestFileOptions = FindFileOptions;
 
+export type WriteOptions = {
+  indent?: number | string;
+  newline?: boolean | string;
+};
+
+export type ResolvedWriteOptions = {
+  indent: number | string;
+  newline: string;
+};
+
 const defaultFindOptions: Required<FindFileOptions> = {
   startingFrom: ".",
   rootPattern: /^node_modules$/,
@@ -97,3 +109,35 @@ export function findFarthestFile(
 ): Promise<string> {
   return findFile(filename, { ..._options, reverse: true });
 }
+
+export async function resolveWriteOptions(
+  path: string,
+  options: WriteOptions
+): Promise<ResolvedWriteOptions> {
+  const file = existsSync(path) ? await readFile(path, "utf8") : undefined;
+  const indent = options.indent ?? (file ? detectIndent(file).indent : 2);
+  const newline =
+    options.newline === true
+      ? "\n"
+      : options.newline === false
+      ? ""
+      : options.newline ?? (file ? (file.endsWith("\n") ? "\n" : "") : "\n");
+
+  return {
+    indent,
+    newline,
+  };
+}
+
+export async function writeJsonFile(
+  path: string,
+  value: any,
+  options: WriteOptions = {}
+): Promise<void> {
+  const resolvedOpts = await resolveWriteOptions(path, options);
+
+  let content = JSON.stringify(value, undefined, resolvedOpts.indent);
+  content += resolvedOpts.newline;
+
+  await writeFile(path, content);
+}
diff --git a/test/index.test.ts b/test/index.test.ts
index 0d3ac19..3a20026 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1,7 +1,9 @@
 import { fileURLToPath } from "node:url";
+import { readFile } from "node:fs/promises";
 import { dirname, resolve } from "pathe";
 import { describe, expect, it } from "vitest";
 import { expectTypeOf } from "expect-type";
+import detectIndent from "detect-indent";
 import {
   readPackageJSON,
   readTSConfig,
@@ -90,6 +92,36 @@ describe("package.json", () => {
       "string"
     );
   });
+
+  it("write package.json with tab indent", async () => {
+    const path = rFixture("package.json.tab.tmp");
+    const indent = "\t";
+    await writePackageJSON(path, { version: "1.0.0" }, { indent });
+    const file = await readFile(path, "utf8");
+    expect(detectIndent(file).indent).toBe(indent);
+  });
+
+  it("write package.json with 4 space indent", async () => {
+    const path = rFixture("package.json.3space.tmp");
+    const indent = 4;
+    await writePackageJSON(path, { version: "1.0.0" }, { indent });
+    const file = await readFile(path, "utf8");
+    expect(detectIndent(file).indent).toBe("    ");
+  });
+
+  it("write package.json with newline", async () => {
+    const path = rFixture("package.json.newline.tmp");
+    await writePackageJSON(path, { version: "1.0.0" }, { newline: true });
+    const file = await readFile(path, "utf8");
+    expect(file.endsWith("\n")).toBe(true);
+  });
+
+  it("write package.json with no newline", async () => {
+    const path = rFixture("package.json.no-newline.tmp");
+    await writePackageJSON(path, { version: "1.0.0" }, { newline: false });
+    const file = await readFile(path, "utf8");
+    expect(file.endsWith("\n")).toBe(false);
+  });
 });
 
 describe("tsconfig.json", () => {