Developer Toolkit
A comprehensive suite of browser-based utilities for modern developers. Encode & decode data, debug JWT tokens, validate certificates, format JSON/YAML/XML, test regex patterns, run jq queries, convert markdown, and more — all with zero installation required.
Explore Dev-Tool →Format and minify JSON instantly with syntax highlighting. Explore nested structures as an interactive collapsible tree. Search keys and values, validate syntax, and copy formatted output — all in your browser.
Parse, format, and validate XML documents with pretty-print and collapse tree view. Highlight attributes, namespaces, and XML declarations. Handle malformed XML with error details.
Convert Unix timestamps (seconds/milliseconds) to human-readable dates. Work with timezones, daylight saving, and custom formats. Supports past/future date calculations and relative time display.
Decode JWT tokens (header + payload) and inspect claims instantly. Verify HS256/HS384/HS512 signatures with your secret key. Expiry validation, claims inspection, and formatted JSON output.
Encode text to Base64 or decode Base64 back to plain text. Toggle between standard Base64 and URL-safe variant (Base64url) for web APIs. Auto-detect input format and handle multi-line input.
Percent-encode special characters in URLs and query strings. Decode URL-encoded strings back to readable text. Parse URL components (protocol, host, path, query, hash) and build URLs safely.
Pomodoro-style focus timer with customizable work/break intervals. Track tasks, set goals, and view statistics. Visual progress bar, audio alerts, and persistent timer across sessions.
Generate cryptographic hashes: MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA3-256, Keccak-256, and more. Paste text or file content — get checksums instantly. Compare hashes with side-by-side comparison.
Convert YAML to JSON and JSON to YAML with validation. Pretty-print with customizable indentation. Detect syntax errors with line-by-line error messages. Handles anchors, aliases, multi-document YAML.
Build and test regular expressions with real-time match highlighting. View capture groups, named groups, and match indices. Preset patterns for common use cases — email, URL, phone, and more.
Run jq filters on any JSON data in your browser — no install needed. Full jq language support via WebAssembly. Built-in function reference, syntax highlighting, and error handling.
Fix line ending issues instantly. Convert between Windows (CRLF), Unix/Linux (LF), and Classic Mac (CR). Drag-and-drop file upload, auto-detect source format, and one-click download.
Auto-generate JSON Schema from sample JSON data. Validate JSON against any draft (Draft-06 through 2020-12). Explore schema structure as an interactive tree with field types, required fields, and constraints.
Pick colors from any image — hover to see RGB, HEX, and HSL values in real time. Click to pin colors to your palette. Export as CSS, Tailwind, or SVG. Supports PNG, JPG, WebP, GIF.
Paste any base64-encoded image to preview it instantly. Supports raw Base64 and data URI format (data:image/png;base64,...). Zoom, copy as markdown, and download as file.
Resize images to exact dimensions or scale by percentage. Compress for web optimization with quality control. Output as WebP, JPEG, PNG, or GIF. Batch resize and maintain aspect ratio.
Convert HTML to PDF directly in your browser — no server uploads. Set page size (A4, Letter, Legal), margins, and orientation. Preview before download, include custom CSS.
Convert Markdown to HTML instantly with GitHub Flavored Markdown (GFM) support. Live preview side-by-side, syntax highlighting for code blocks, and copy raw HTML or embedded HTML.
Transcribe speech to text using your browser's microphone. Real-time transcript with interim results. Click to insert pauses in the recording. Works in Chrome — no server, no data sent.
Generate X.509 SSL/TLS certificates and SSH key pairs in your browser. Create self-signed certificates, CSRs, and private keys. Password-protected ZIP download — private keys never leave your device.
Decode PEM certificates and view full details — subject, issuer, validity dates, serial number, fingerprints (MD5/SHA-1/SHA-256), SANs, key usage, and extensions.
Convert images to Base64 strings for embedding in HTML, CSS, or JSON. Drag-and-drop or click to upload. Output as raw Base64 or ready-to-use HTML img tag. No upload — 100% browser-side.
Algorithm Illumination
Unlike static videos or textbooks, this tool lets you control the pace — step forward, pause, and rewind through every comparison and swap. Built by developers, for developers and students preparing for technical interviews. Covers sorting, searching, graph traversal, dynamic programming, and more — all animated in real time in your browser.
Explore Algo →Visualize bubble sort, merge sort, quick sort, heap sort, insertion sort, selection sort, and counting sort — step by step with color-coded comparisons and swaps. Compare time/space complexity for each algorithm side-by-side.
Watch binary search, linear search, exponential search, and jump search execute in real time. See mid-point calculations, range narrowing, and target comparisons with step-by-step animations. Works on sorted arrays of any size.
Explore BFS, DFS, Dijkstra's shortest path, Bellman-Ford, and Prim's MST with interactive step-by-step visualizations. Build custom graphs, watch frontier expansion, backtracking, and shortest path computation unfold in real time.
Master classic divide-and-conquer: maximum subarray (Kadane's), closest pair of points, median of two sorted arrays, and binary search with recursive tree visualization. Watch divide, conquer, and combine phases animate step by step.
Activity selection, Huffman coding, and Jump Game visualization. Watch greedy choices, optimal substructure unfolding, and understand when greedy strategies work vs. when they fail. Compare to DP for the same problems.
Learn BST, AVL trees, and tree traversals — inorder, preorder, postorder, and level-order (BFS). Watch rotations, rebalancing, insertion, and deletion with animated tree transformations. Understand self-balancing mechanisms.
Master Fibonacci, 0/1 knapsack, longest increasing subsequence, coin change, edit distance, and more. Watch DP table fill step by step, understand optimal substructure and overlapping subproblems. Build intuition for tabulation vs. memoization.
Explore string matching algorithms — naive search, KMP, Boyer-Moore, and Rabin-Karp. Watch pattern sliding, failure function computation, and rolling hash techniques unfold with detailed step-by-step animations.
Master singly and doubly linked list operations — insert, delete, search, and reverse. Visualize pointer manipulation, dummy head technique, and sentinel nodes. Watch traversal, node removal, and reversal with pointer animation.
Master pointer manipulation problems — cycle detection (Floyd's tortoise and hare), linked list intersection, palindrome detection, and reversal techniques. Understand two-pointer strategies for linked list challenges.
Visualize KMP, Boyer-Moore, and Rabin-Karp pattern matching algorithms. Watch prefix function computation, bad character heuristic, and rolling hash matching unfold with character-by-character animations. Compare algorithm efficiency.
Learn N-Queens, Permutations, Subset Sum, and Sudoku solver with backtracking visualization. Watch decision tree expansion, pruning, and backtracking with color-coded states. Understand when exploration vs. pruning occurs.
Advanced graph algorithms: Tarjan's & Kosaraju's SCC, Dijkstra with path reconstruction, Bellman-Ford negative cycle detection, Floyd-Warshall all-pairs shortest path, Kahn's topological sort, and cycle detection. Build complex weighted graphs and watch algorithms unfold.
Visualize hash table operations — insertion, deletion, and search with collision handling. Explore separate chaining and open addressing (linear/quadratic probing). Watch load factor, rehashing, and bucket distribution with animated buckets and chains.
Explore advanced string indexing: suffix arrays, Z-algorithm, Manacher's algorithm for longest palindrome, and Lempel-Ziv (LZ) decomposition. Watch prefix matching, longest common extensions, and pattern searching in text.
Binary Search Tree operations — insert, search, delete, rotate (LL, RR, LR, RL), and AVL self-balancing with height tracking. Watch node promotions, rotations, and tree rebalancing animate step by step. Compare AVL vs. Red-Black trees.
Queue-based algorithm problems: LRU Cache simulation, Rotting Oranges grid problem, and other BFS queue patterns. Watch queue state changes, eviction processes, and time-step progression with grid visualization and state tracking.
Learn Big-O notation with interactive complexity graphs comparing O(1) through O(n!) across different input sizes. Analyze time/space complexity of code snippets, see constant factors, and understand why algorithm choice matters for scalability.
Intermediate linked list challenges: flatten nested linked lists, detect palindromes, implement LRU cache from scratch, and reverse in groups. Build complex pointer manipulations with detailed step-by-step guidance and edge case handling.
Brain Training Games
Play brain-training games rooted in neuroscience to strengthen memory, focus, and cognitive skills. All games run entirely in your browser — no account needed, no data collected.
Explore All →Watch the flashing pattern and repeat it back. Trains working memory, attention, and processing speed.
Classic sliding tile puzzle. Use arrow keys to join numbers and reach 2048. Features score tracking and best score persistence.
Classic 9×9 Sudoku with 4 difficulty levels, undo, notes, hints, and timer. Train logical reasoning.