Local-First · Private · Free

Local File Utilities

Conversions and encryption are processed entirely on your device. Your files are never uploaded to any server. No size limits, no tracking, and no paywalls.

Image Converter

Convert PNG, JPG, WEBP, BMP, and GIF with custom compression control.

Images

PDF Merge & Split

Combine multiple PDFs or extract pages/ranges into a ZIP folder.

PDF

CSV ⇄ JSON

Convert structured spreadsheet files into JSON arrays and back instantly.

Data

Text Toolkit

Format, clean, trim whitespace, change case, and analyze text statistics.

Text

Audio to WAV

Decode local MP3, OGG, or AAC audio and extract uncompressed WAV files.

Audio

ZIP Builder

Package multiple directories or groups of files into a compressed ZIP.

Archive

Image Converter

Convert images locally in your browser with real-time compression settings.

Drag and drop your image here, or browse files

Uploaded preview

PDF Merge & Split

Combine multiple PDF files or extract pages into a new document securely.

Merge PDF Files

Select and arrange multiple files to merge them into a single PDF.

Add PDF files to merge, or browse

Split PDF File

Split a PDF into single pages, or define custom page ranges to package in a ZIP.

Select PDF file to split, or browse

CSV ⇄ JSON Converter

Convert spreadsheet datasets to structured JSON objects and back locally.

Drag and drop a CSV or JSON file here, or browse

Text Toolkit

Clean and transform text strings or text files locally.

Drag and drop a text file here, or browse

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Audio to WAV Converter

Extract raw, uncompressed 16-bit PCM WAV tracks from common audio formats locally.

Drag and drop an audio file (MP3, OGG, M4A, etc.), or browse

ZIP Builder

Bundle multiple files into a single zip archive locally without uploads.

Select multiple files to compress, or browse

Zero-Knowledge Sharing

Encrypted Share

Files are encrypted with AES-GCM (256-bit) inside your browser. The decryption key is kept in the URL hash fragment and never reaches our servers.

Upload & Encrypt

Files are partitioned, encrypted locally, and securely stored temporarily.

Decrypt & Download

Paste a secure link or file ID to retrieve and decrypt the file on your device.

Nonprofit Technology

Open Tech Tools is a free, local-first utility suite operated by Open Tech Academy. Everything runs inside your browser to ensure maximum privacy and accessibility for all students, developers, and educators.

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