Free online tools

22 tools I built because I needed them, kept online because other people did too. Most run entirely in your browser: no account, no upload, no watermark. I maintain these personally — if a number looks wrong, email me and I will fix it.

• TikTok Video DownloaderSave any public TikTok as an MP4 with the sound intact. No watermark overlay added, no signup, no app install, and nothing kept afterwards.Video tools
• YouTube Video DownloaderGrab a YouTube clip as MP4 video or M4A audio. Audio is the default because it is a fraction of the size and finishes far quicker.Video tools
• Instagram Video DownloaderDownload a public Instagram reel or video post as a playable MP4 file, with audio merged back in. Works from a link — no login, no extension.Video tools
• Facebook Video DownloaderSave a public Facebook video or reel to your device as MP4. Paste the post link, choose a size, and the sound is merged back in for you.Video tools
• Loom Video DownloaderKeep a copy of a Loom recording as an MP4 before a share link expires or a workspace plan lapses. Works on public share links only.Video tools
• Percentage CalculatorWork out a percentage of a number, what share one number is of another, or the change between two values. Shows the working. Runs in your browser.Calculators · runs offline
• Loan and EMI CalculatorFind the monthly instalment on any loan and see the full repayment schedule, month by month, with interest and principal split out.Calculators · runs offline
• Compound Interest CalculatorProject savings growth with optional regular contributions, at any compounding frequency, and see the balance year by year.Calculators · runs offline
• Word CounterCount words, characters, sentences and paragraphs as you type, with reading and speaking time. Handles Chinese and Sinhala. Nothing uploaded.Text tools · runs offline
• Case ConverterSwitch text between camelCase, snake_case, kebab-case, Title Case and eight more. Handles acronyms correctly. Includes a URL slug maker.Text tools · runs offline
• Text Diff CheckerCompare two texts and see exactly which lines were added, removed or kept, aligned properly rather than line by line. Runs in your browser.Text tools · runs offline
• JSON Formatter and ValidatorPretty-print, minify or sort JSON, and get syntax errors reported by line and column with the offending line shown. Runs entirely offline.Developer tools · runs offline
• Base64 Encoder and DecoderEncode and decode Base64 in your browser, including URL-safe Base64. Handles emoji, Sinhala and Chinese, which btoa-based tools cannot.Developer tools · runs offline
• UUID GeneratorGenerate UUID v4 or the time-ordered v7 in bulk, using your browser's cryptographic randomness. Also validates and inspects existing UUIDs.Developer tools · runs offline
• SHA Hash GeneratorGenerate SHA-256, SHA-384, SHA-512 or SHA-1 hashes of any text in your browser, using the Web Crypto API. Nothing is uploaded.Developer tools · runs offline
• URL Encoder and DecoderPercent-encode or decode URLs and query parameters, and break any URL into its parts. Handles the component and full-URL distinction correctly.Developer tools · runs offline
• Unix Timestamp ConverterConvert a Unix timestamp to a readable date and back, in seconds or milliseconds, with UTC and local time shown side by side.Developer tools · runs offline
• JWT DecoderDecode a JSON Web Token in your browser and read its header, payload and claims. Expiry is checked against your clock. Nothing is ever uploaded.Developer tools · runs offline
• Password GeneratorGenerate strong random passwords or passphrases in your browser, using the same cryptographic randomness your bank does. Nothing is transmitted.Developer tools · runs offline
• CSV to JSON ConverterConvert CSV to JSON and back in your browser, with correct handling of quoted fields, embedded commas and newlines inside cells. Nothing uploads.Developer tools · runs offline
• Aspect Ratio CalculatorWork out an aspect ratio from any width and height, or resize while keeping the ratio. Covers 16:9, 4:3, 1:1, 21:9 and anything else.Image tools · runs offline
• Color Converter and Contrast CheckerConvert a color between HEX, RGB, HSL and OKLCH, and check its WCAG contrast ratio against any background. Everything runs in your browser.Image tools · runs offline

These tools are free and provided as-is, with no guarantee of uptime or accuracy — check anything that matters against a second source. They run entirely in your browser and nothing you enter is uploaded or stored; see privacy.

Built by Kavitha Kanchana, software engineer in Sri Lanka.