Free Online
Tools.
PDF, image, text, and developer tools — 100% browser-based. Your files never leave your device. PDF, image, developer, and text utilities that run entirely in your browser. No file uploads, no watermarks, no signup. Your files never leave your device — the conversion happens client-side using the Canvas, File, and Web Crypto APIs.
- You need a quick PDF, image, or text conversion and don't want to install software.
- You're a developer and want a regex tester, JSON formatter, or color converter in a single tab.
- You're working with sensitive files and need processing that never leaves your machine.
Pick by what you're deciding
The same pages, grouped by the question you're trying to answer.
PDF tasks
Merge multiple PDFs or split one apart — entirely in-browser.
Image processing
Compress, convert, and generate icons using your browser's Canvas API.
Developer utilities
Encode, format, test, and convert — the everyday tooling you reach for at the terminal.
Text & number utilities
Quick text generators, number tools, QR codes, and document boilerplate.
Productivity
Pomodoro timer and the everyday tools that don't need an account.
PDF Tools
2 toolsMerge, split, and extract PDF pages — entirely in your browser. No file uploads, no watermarks.
Image Tools
4 toolsCompress, convert, and transform images using your browser's built-in Canvas API. Zero server processing.
Image Compressor
Reduce JPEG, PNG, and WebP file sizes with adjustable quality.
Image to PDF
Convert images to a multi-page PDF with custom page size and margins.
Image Converter
Convert between JPEG, PNG, and WebP formats instantly.
Favicon Generator
Generate all favicon sizes from an image or custom text/emoji.
Developer Tools
10 toolsJSON formatting, Base64 encoding, CSV conversion, regex testing, diff checking, cron building, Markdown editing, responsive testing, and more.
JSON Formatter
Format, validate, and minify JSON with syntax error detection.
Base64 Encoder / Decoder
Encode text or files to Base64, decode Base64 strings back.
CSV to JSON
Convert CSV to JSON and back with delimiter auto-detection.
Color Converter
Convert between HEX, RGB, HSL, HSV, and CMYK with contrast checker.
Timestamp Converter
Unix timestamp to date and back, with timezone support.
Regex Tester
Test regular expressions with real-time matching, capture groups, and replacements.
Diff Checker
Compare two texts side-by-side with highlighted additions, deletions, and changes.
Cron Expression Builder
Visual cron schedule builder with human-readable descriptions and next run previews.
Markdown Editor
Write Markdown with live HTML preview, formatting toolbar, and export options.
Responsive Design Tester
Preview any website at different screen sizes with preset device dimensions.
Text & Number Tools
3 toolsWord counting, case conversion, line sorting, lorem ipsum generation, percentage calculations, and number base conversions.
Utilities
1 toolQR codes, timers, invoices, legal document generators, aspect ratios, and internet speed — handy tools for everyday use.
QR Code Generator
Custom QR codes with colors, logos, and 12 content types.
Aspect Ratio Calculator
Calculate ratios, scale dimensions, and browse common screen sizes.
Internet Speed Test
Test download, upload, ping, and jitter — no app required.
Pomodoro Timer
Configurable focus timer with break intervals, notifications, and session statistics.
Invoice Generator
Create professional invoices with line items, taxes, and discounts — download as PDF.
Privacy Policy Generator
Generate a customized privacy policy with GDPR and CCPA compliance support.
Terms of Service Generator
Generate customized terms of service for websites, apps, and SaaS products.
Frequently asked questions
Do my files actually stay on my device?
Yes. Every tool here uses browser-only APIs (FileReader, Canvas, Web Crypto, pdf-lib client-side, etc.). There's no upload endpoint. You can verify by opening DevTools → Network and confirming no outgoing requests when you process a file.
Is there a file-size limit?
Practically, ~250 MB per file before browser memory starts to constrain you. PDF merge of 50+ files or compressing a 4K image may slow down older devices. For very large jobs, batch them.
Do these tools work offline?
Yes. After first visit the service worker caches each tool. Add to home screen on phone or desktop; the JSON formatter and color converter still work on a plane.
Why is the regex tester here and not in developer tools elsewhere?
Because we don't run a separate developer surface. Calculover tools live alongside calculators — the same engineering team builds both, the same UI conventions apply. If you have a developer-tool request, the contact form goes to the same backlog.
Are there any tools you won't add?
We don't ship tools that require server upload (true file-conversion services), tools that compete with mature open-source CLIs (image-magick, ffmpeg), or anything that depends on a paid third-party API. Everything here is client-side, free, and signup-free by design.