Free online tools and calculators
Quick answers for everyday numbers, from what your car costs to run to what a percentage change means. Every tool is free and works in your browser.
Tools
All tools- Crop Image to Square (1:1)Crop a photo to an exact 1:1 ratio and download it at the size you need.
- Crop Image to 4:3Crop a photo to an exact 4:3 ratio and download it at the size you need.
- Crop Image to 3:2Crop a photo to an exact 3:2 ratio and download it at the size you need.
- Crop Image to 16:9Crop a photo to an exact 16:9 ratio and download it at the size you need.
- Crop Image to 3:4Crop a photo to an exact 3:4 ratio and download it at the size you need.
- Crop Image to 9:16Crop a photo to an exact 9:16 ratio and download it at the size you need.
- Open RAR Files OnlineBrowse RAR4 and RAR5 archives, extract selected files and download them or a ZIP, without WinRAR.
- Open 7Z Files OnlineBrowse 7Z archives, extract selected files and download them or a ZIP, without installing 7-Zip.
- JSON to Excel ConverterFree JSON to Excel converter online: pick records, flatten nested JSON, preview and download a real XLSX file.
- Free Picture Stencil MakerTurn a photo into a printable stencil with bridges, touch-up, PNG and vector SVG downloads.
- Low Quality Image MakerMake images intentionally worse: JPEG artifacts, pixelation, blur, noise and deep-fried effects.
- MP3 SplitterSplit an MP3 at custom points, into equal parts or at pauses, and download MP3 files or a ZIP.
- GIF Background RemoverRemove white or solid-colour backgrounds from animated GIFs and download a transparent GIF.
- Large File ViewerOpen huge text, log, CSV and JSON files up to 2 GB: browse by page, search and jump to any line.
- Binary File ViewerView any file as hex, ASCII and binary; search bytes and detect file signatures.
- DICOM ViewerOpen CT, MRI and X-ray DICOM files in your browser, privately.
- XML Sitemap GeneratorCrawl a website or paste URLs, review them, and download a valid sitemap.xml.
- Ambigram GeneratorTurn a word or word pair into a rotational ambigram and download it as PNG, SVG or JPG.
- Dumb Charades Word GeneratorRandom words, movie names and actions to act out, with a round timer and no repeats.
- Dumb Charades Movie GeneratorRandom movie titles to act out, by difficulty.
- Dumb Charades for KidsEasy, child-friendly charades words: animals, actions and objects.
- Office Dumb CharadesWork-friendly charades prompts for Fun Friday and team icebreakers.
- Online GUID GeneratorGenerate UUID v4, v7, v1, v3, v5 and v6 identifiers in bulk, with copy and download.
- UUID v4 GeneratorRandom version 4 UUIDs, one or a thousand at a time.
- UUID v7 GeneratorTime-ordered version 7 UUIDs with their embedded timestamps.
- UUID ValidatorCheck the format, version and variant of one or many UUIDs.
- UUID DecoderSee the version, variant and embedded timestamp inside a UUID.
- Credit Card Generator (Test Data)Generate synthetic, Luhn-valid test card numbers for payment-form testing.
- Fuel Savings CalculatorSee what you spend on fuel each month and how much better fuel economy could save.
Guides
All guidesDesign & Lettering
How to Make an Ambigram (Online or by Hand)
Create a rotational ambigram from one or two words, from checking letter pairs to refining and exporting the design.
File Guides
How to View a Binary File (BIN, DAT and Unknown Files)
See inside .bin, .dat and unidentified files with hex viewers, built-in commands and a browser-based tool.
Developer Guides
The Luhn Algorithm Explained (With a Worked Example)
How the Luhn check digit works, a step-by-step example, short code in JavaScript and Python, and what it can't do.
File Guides
How to Open DICOM (.dcm) Files on Any Computer
Free ways to view .dcm scans and full CT or MRI series on any device, plus what to do when a file won't display.
Games & Party Ideas
How to Play Charades With Kids (Easy Rules That Work)
Simplified rules, easy prompts, helpers for non-readers and cooperative scoring that keep children engaged.
Games & Party Ideas
How to Act Out Movie Titles in Charades
Signal the film, choose between acting the words or a famous scene, and handle small words, names and numbers.