Text & documents
Encoder/DecoderURL, Base64, HTML
Text convertercamelCase, snake_case...
Text DiffCompare two texts
LaTeXPreview mathematical formulas
MarkdownReal-time preview
MermaidDiagrams as code
DiagramsVisio-style visual editor, Mermaid import
String escaperJS, JSON, SQL, Regex, HTML, URL
Unicode / ASCIICharacter information
Numbers & maths
CalculatorMath expressions + LaTeX
Base converterBase 2 to 64
Unit systembits, bytes, SI, IEC
Subnet / CIDRNetwork calculator
Timestamp and datesUnix, time zones, formats
Date calculatorDays between dates, exact age, day of the week
Data & formats
Format converterJSON, YAML, Properties, ENV, CSV
JSON FormatterFormat and validate JSON
Regex TesterRegular expressions
JSON DiffStructurally compare two JSONs
Code formatterSQL, CSS, HTML, JavaScript
DB StudioVisual Postgres database in the browser
SQL LabValidate, run and optimize SQL with real Postgres
Giant file viewerOpen huge CSV/logs without loading them
Visual ETL flowTransform data by chaining nodes
Security
Text anonymizerRedact PII and secrets (reversible)
JWT InspectorDecode JWT tokens
Auth flowsBasic, JWT and OAuth2 step by step
Hash generatorSHA-256, SHA-384, SHA-512
Password & UUID generatorPasswords and UUIDs
Development & DevOps
CronGenerator and validator
Docker → ComposeConvert docker run to Compose
Skaffold multi-configDependency graph and requires validation
Linux: permissions and userschmod, chown, useradd and groups
URLParse and build URLs
Random dataNames, emails, IPs, UUIDs...
ElectronicsOhm's law, series/parallel resistors
Logic GatesAND, OR, NOT and more gate simulator
Quantum simulatorQubits, gates, superposition and entanglement
HammingError detection
Nginx/Apache SPA configGenerate config to serve a SPA
SemverSemantic version ranges
CORS ExplainerAnalyse your server's CORS headers
Cert inspectorAnalyse X.509 certificates in PEM format
Rate LimiterSimulate Token Bucket and Fixed Window
Assembly simulatorSimplified MIPS ISA · step-by-step · registers & memory
Context ForgePack and shield your project for AI
Artificial Intelligence
LLM costsSimulate monthly spend
Prompt builderSystem prompt for AI agents
EmbeddingsSimilarity, 2D map and RAG
Local AIChat, summarization, translation & sentiment in-browser
TokenizerVisualize tokens, compare models, estimate costs
Probability for AIDistributions, softmax, Bayes and entropy
Gradient descentSGD, Momentum, RMSProp, Adam
Neural networkTrain an MLP and watch the boundary form
Mini-LLMTrain a language model with your text
Dimensionality reducerPCA, t-SNE and UMAP, live
Confusion matrix & ROCThreshold, precision/recall, ROC/AUC, PR
Clustering (k-means, DBSCAN)Discover groups without labels
Attention visualizerWhat each word looks at in a transformer
Convolution & CNN filtersImage filters and feature maps
Decision treeDecision regions + the tree
Fourier & convolutionFFT spectrum and signal filters
DiffusionThe noise behind Stable Diffusion
Regression & MLELeast squares, overfitting, ridge
Markov chainsStates, stationary distribution and text
Hypothesis testingp-values, t-test, χ², ANOVA and power
OCR — Image to textExtract text from images, 100% local
Finance
InflationYear-by-year purchasing power erosion
Compound interestCapital + contributions + compound interest
Mortgage / loanMonthly payment and French amortization schedule
Split expensesWho owes whom and how much
Health & Wellness
BMI & healthBMI, ideal weight, BMR and sleep cycles
Productivity
PomodoroTime-block work technique
StopwatchWith laps, stages and history
Games & Entertainment
DiceTables with numeric and symbolic dice
ScorekeeperPoints per player with game timer
Random pickerPick a random item from a list
Name generatorReal, fantasy, sci-fi, Norse names
Multimedia & design
Color HEX/RGB/HSLColor converter
QR CodeGenerate QR codes
ImagesResize, convert, Base64
PDF ToolsMerge, extract, watermark
ChartsVisualize data with charts
WCAG ContrastWCAG AA/AAA contrast ratio
Business
Meeting costHow much does each meeting really cost?
SLA / UptimeAvailability percentage ↔ downtime
Break-evenCost and revenue break-even point
Burn rate / RunwayHow long does your cash last?
A/B TestStatistical significance of experiments
DORA MetricsClassify your team by DevOps metrics
UTM BuilderBuild and decode URLs with UTM parameters
How to use
What it shows

Each flow is drawn as a sequence diagram: the actors (user, client, servers) are columns and the messages are arrows over time. Press Play or ⏭ to step through it.

Edit it

Change the client_id, redirect_uri, scope, credentials, etc. and the diagram regenerates. Click any arrow to inspect the real HTTP request and its explanation.

Flows

Basic (username:password in Base64), Bearer/JWT, Authorization Code, Code + PKCE (recommended today), Implicit (legacy), Client Credentials (machine-to-machine), Device Code (TVs/CLI) and Refresh Token (renew without re-login).

Export and decode

On any step with an HTTP request you can copy it as a curl command to replay it in your terminal. If the step carries a JWT, open it in the JWT decoder to inspect its header and payload.

Attacks and MITM

Enable an attack to see an Attacker actor and the malicious steps (in red): credential sniffing, alg:none, code interception without PKCE, CSRF from a missing state. Toggle the mitigation and the attack is neutralized (in green), showing why it fails.

Compare

On the Compare tab you pick a flow on each side (or a preset pair) and they are drawn together. Equivalent steps line up on the same row (same /authorize, same /token…) so the difference stands out, and a summary lists which params and actors each one adds. Click any arrow to inspect it.

Tools

The Tools tab gathers practical OAuth utilities, all in the browser: generate and verify PKCE pairs (S256), build a copy-ready /authorize URL and parse a callback URL (extracts code/state or the fragment tokens and detects errors).

Auth flowsBasic, JWT and OAuth2 step by step
Authentication flowsVisualize and edit Basic, Bearer/JWT and OAuth2 step by step
Attack:
Parameters
1 / 9
Usuario / NavegadorCliente (App)Servidor de autorizaciónServidor de recursos (API)Pulsa "Iniciar sesión"302 → /authorizeGET /authorize (login + consentimiento)302 → redirect_uri?code&stateGET /callback?code&statePOST /token200 { access_token, id_token, refresh_token }GET /api + Authorization: Bearer200 OK
Paso 1Pulsa "Iniciar sesión"

El usuario inicia el login en la aplicación cliente.