Tools for people who write code

Format, check and preview the text you work with every day, on your own machine. Nothing is uploaded, no sign-up.

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Editor

Markdown Preview

Write Markdown on the left and watch it render on the right — tables, code, math, diagrams and more.

Live preview · Export HTML/PDF

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Developer

JSON Lab

An all-in-one JSON toolkit: format, validate with pinpoint errors, browse the tree, query with JSONPath, convert to YAML/CSV/TypeScript, infer a schema and diff two documents.

Validate · Tree · JSONPath · Diff

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Everyday apps

Timetables, photos, instruments and cards live in the Apps section, one click away.

Apps