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Code Playgrounds & Testers
Run and test code online: regex, JavaScript, Python, SQL, JSON path, XPath and more. 53 free tools that run in your browser, no sign-up needed.
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Online Python CompilerRun Python 3 in your browser with input(), numpy, pandas, charts and share links.JSON EditorEdit JSON in a tree and as code side by side: add, rename, drag, change types, undo and download.Unzip FilesOpen and extract ZIP files online.RAR & 7z ExtractorOpen RAR, 7z and other archives online and extract files.Regex TesterTest and debug regular expressions live.File Info ViewerCheck file size, type, date and MD5/SHA hashes.SQLite ViewerOpen .db and .sqlite files in your browser, browse tables and run SQL queries.DOCX ViewerOpen and read Word .docx files in your browser, then print or save them as HTML.EPUB ReaderOpen and read EPUB e-books in your browser with pages, a table of contents and font controls.What Is My BrowserSee your browser, version, OS, engine, screen and which web features it supports.Font ViewerPreview TTF, OTF, WOFF and WOFF2 fonts with sample text, waterfall, glyphs and metadata.Markdown EditorWrite Markdown with a toolbar, live split preview, autosave and .md or HTML export.Regex Cheat Sheet75+ ready-to-use regex patterns for emails, URLs, IPs and dates, each with a live test box.JavaScript Keycode FinderPress any key to see its JavaScript key, code, keyCode, which, location and modifiers.QR Code ScannerScan QR codes with your camera or from an image and safely read the link or text.RAID CalculatorUsable capacity, efficiency and fault tolerance for RAID 0, 1, 5, 6, 10, 50 and 60 arrays.JSONPath TesterTest JSONPath expressions live: filters, slices, wildcards and recursive search, with matches highlighted.Mermaid Diagram EditorWrite Mermaid code and see flowcharts, sequence, Gantt and ER diagrams live. Export SVG or PNG.Country Codes ListSearch ISO 3166 alpha-2, alpha-3 and numeric country codes with calling codes and TLDs.CSS Selector TesterTest CSS selectors on your HTML: highlighted matches, match count and specificity.Git Cheat SheetSearchable Git command reference by task, with copy buttons and an undo/rename/fix wizard.HAR File ViewerOpen a .har file to see a waterfall timeline, headers, bodies, timings and size totals.jq PlaygroundRun jq filters on JSON in your browser with live output, flags and an example library.Markdown Cheat SheetInteractive Markdown syntax reference: edit every example and see the live rendered preview.Regex ExplainerPaste a regular expression and get a plain-English breakdown, railroad diagram and flag notes.XPath TesterTest XPath expressions on XML or HTML: highlighted matches, node paths, values and examples.EML File ViewerOpen .eml email files to read the message, headers and raw source and save attachments.Graphviz Online ViewerWrite Graphviz DOT code and render graphs live; switch layout engines, export SVG or PNG.JavaScript Online CompilerWrite and run JavaScript in your browser with a console, timing, error lines and share links.Jupyter Notebook ViewerOpen .ipynb files and read code, Markdown, math, tables, plots and errors without Python.LaTeX Table GeneratorEdit a table like a spreadsheet or paste from Excel and get LaTeX tabular or booktabs code.Log File ViewerOpen huge log files with level colors, regex and time filters, JSON pretty-print and tail -f.Logic Gate SimulatorBuild logic circuits with AND, OR, NOT, XOR gates and flip-flops; see live outputs and truth tables.MSG File ViewerOpen Outlook .msg emails in your browser: sender, recipients, body, headers and attachments.Online Code EditorVS Code-style editor in your browser: tabs, 50+ languages, find/replace, autosave.Online Hex EditorOpen any file as hex and ASCII, edit bytes, search, inspect values and save the result.PHP Online CompilerRun PHP 8 code in your browser with output, HTML preview, error lines and share links.PlantUML EditorWrite PlantUML and see sequence, class, activity and more diagrams live. Export SVG or PNG.Sorting Algorithm VisualizerWatch bubble, insertion, merge, quick, heap and radix sort step by step with live counters.Lottie ViewerOpen Lottie JSON or .lottie files to play, pause, scrub frames, change speed and see details.Diff ViewerPaste a git diff or .patch file and view it side by side or inline, with file navigation.EditorConfig GeneratorBuild an .editorconfig with indent, charset, line endings and trim rules per file pattern.Folder Compare ToolCompare two folders by file list, size and SHA-256 hash, then open a text diff of changed files.Glob Pattern TesterTest glob patterns like **/*.js, {a,b} and !exclusions against a list of file paths.JMESPath TesterEvaluate JMESPath expressions against JSON live, the query language used by the AWS CLI.MongoDB Query TesterTest MongoDB find filters, projections and aggregation pipelines on sample JSON documents.Semantic Version CalculatorBump, compare, sort and test SemVer versions against npm ^, ~ and x ranges.XSLT TesterRun an XSLT 1.0 stylesheet on XML in your browser and see the output as HTML, XML or text.ASCII Diagram EditorDraw boxes, arrows and text on a character grid and copy plain-text diagrams for code and READMEs.DBF File ViewerOpen dBase .dbf files and shapefile tables, search and sort records, export CSV or XLSX.MBOX File ViewerOpen .mbox mail archives: list and search messages, read them, save attachments, export EML.MDB File ViewerOpen Access .mdb and .accdb databases in your browser: list tables, view rows, export CSV.Shapefile ViewerView zipped shapefiles on a map with the attribute table, then export to GeoJSON or CSV.
About Code Playgrounds & Testers
Run and test code in the browser: regex, JavaScript, Python, SQL, JSON and more, plus viewers for SQLite databases and documents. Great for quick experiments without setting up a local environment.
Most used here: Online Python Compiler, JSON Editor and Unzip Files.