TechWhack
Free online tools: merge PDF, compress images, format JSON
TechWhack is a big shelf of single-purpose web tools. The PDF section merges, splits, compresses and converts. The image section compresses and resizes. Developers get a JSON formatter, base64, regex and JWT tools, and there are network lookups, password generators, SEO checkers, calculators and a fake tweet generator. Each tool opens on its own page and does one job.
Our verdict
A good bookmark when you need a quick fix and do not want to hunt for a trustworthy site or create an account. The range is the draw: PDF, image, developer, network and SEO tools sit in one place with the same layout, so once you have used one you know them all. The site states that most tools run in your browser, so files stay on your device.
Why we like it: No sign-up, no paywall and no watermark on output, which is rarer than it should be for PDF and image tools. Tools are grouped by job, each category points to its most popular tool, and new ones keep showing up. Common searches like an hours calculator or a UUID generator get a clean page instead of an ad maze.
The catch: It is a collection, not one polished app. Tool quality varies, and heavy jobs such as big PDFs depend on your own device since most work happens in the browser. Do not expect a tool for every niche format.