rdwr

File I/O for modern browsers. Allows reading/writing bytes and low-level data types from/to files on the user's filesystem, preferring streaming methods when available.

Web Demo | Source Code

Feature Matrix

| | Chrome | Edge | Firefox | Opera | Safari | |:----------------|:------:|:----:|:-------:|:-----:|:------:| | Read | ✅ | ✅ | ✅* | ✅ | ✅* | | Streaming Read | ✅ | ✅ | ✅ | ✅ | ✅ | | Write | ✅ | ✅ | ✅* | ✅ | ✅* | | Streaming Write | ✅ | ✅ | ❌ | ✅ | ❌ |

* Some configuration options are unsatisfiable (see here).

Usage

import { readFromFile, writeToFile } from "rdwr-ts";

// Read a file with suggested name
async function read(name) {
    const reader = await readFromFile({ name });
    try {
        const bytes = await reader.readBytes(4);
        const short = await reader.readInt16();
    } finally {
        await reader.close();
    }
}

// Write a file with suggested name
async function write(name) {
    const writer = await writeToFile({ name });
    try {
        await writer.write(new Uint8Array([0xCA, 0xFE, 0xBA, 0xBE]));
        await writer.writeInt16(42);
    } finally {
        await writer.close();
    }
}

License

   Copyright 2025 Xavier Pedraza

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.