DevKit

Editors with live preview, plus encode, convert, and crypto utilities — free, private, in your browser.

Editors

JSON Editor

Edit, format, minify, and preview JSON with tree and table views — convert to YAML when needed.

Free online JSON editor with live structured preview. Format or minify JSON in your browser, validate as you type, and convert to YAML or TOML when needed. Nothing is uploaded — your data stays on your device.

What you can do

Live tree preview of objects and arrays
Arrays of objects render as editable tables
Primitive arrays show as numbered value tables
Click any string, number, or boolean in the preview to edit in place
Pretty-print and minify with one click
Convert JSON to YAML or TOML without leaving the page
Runs fully offline in your browser for privacy

Category: Editors

json
editor
preview
tree
table
format
pretty
minify
validate
array table

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit, format, minify, and preview JSON with tree and table views — convert to YAML when needed.

YAML Editor

Edit, format, and preview YAML as a tree or table — convert to JSON when needed.

Free online YAML editor with a structured live preview. Format YAML, inspect nested maps and lists as a tree or table, and convert to JSON when you need a portable interchange format. Processing happens locally in your browser.

What you can do

Structured preview for maps, sequences, and nested documents
Object arrays displayed as tables for easier scanning
Inline edit of scalar values from the preview pane
Format YAML and convert to JSON
Useful for Kubernetes manifests, CI configs, and app settings
Private — YAML never leaves your machine

Category: Editors

yaml
yml
editor
preview
tree
table
format
json
convert

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit, format, and preview YAML as a tree or table — convert to JSON when needed.

TOML Editor

Edit, format, and preview TOML as a tree or table — convert to JSON when needed.

Free online TOML editor with structured preview. Format configuration files, explore tables and arrays visually, and convert to JSON for tooling that expects JSON. Everything runs client-side.

What you can do

Tree and table preview for TOML tables and arrays
Inline editing of primitive values in the preview
Format TOML and convert to JSON
Ideal for Cargo, pyproject, and app config files
No upload, no account required

Category: Editors

toml
config
editor
preview
tree
table
format
json

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit, format, and preview TOML as a tree or table — convert to JSON when needed.

CSV Editor

Edit CSV with a sortable table preview.

Free online CSV editor with a sortable table preview. Paste spreadsheet-style data, sort columns, and edit cells while keeping everything in your browser.

What you can do

Sortable interactive table preview
Edit CSV text and see rows update live
Handy for quick data cleanup without Excel
Private local processing

Category: Editors

csv
table
spreadsheet
editor

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit CSV with a sortable table preview.

Markdown Editor

Write and preview Markdown live.

Free online Markdown editor with live HTML preview. Write docs, READMEs, and notes with instant rendered output. Parsing runs in your browser.

What you can do

Live rendered Markdown preview
Split, editor-only, or preview-only layouts
Great for README drafts and documentation
No server round-trips

Category: Editors

markdown
md
preview
gfm
editor

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Write and preview Markdown live.

HTML Editor

Edit HTML and preview in a sandboxed frame.

Free online HTML editor with a sandboxed live preview. Experiment with markup and see the result in an isolated iframe so scripts stay contained.

What you can do

Sandboxed iframe preview
Optional JavaScript in the preview frame
Split view for editing and previewing together
Useful for snippets and quick layout checks

Category: Editors

html
preview
iframe
sandbox

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit HTML and preview in a sandboxed frame.

SQL Editor

Write and format SQL locally with a readable preview.

Free online SQL editor that formats queries locally for readability. Paste SELECT statements and messy scripts to get clean, keyword-cased SQL without sending queries to a database.

What you can do

Local SQL formatting and pretty-print
Readable preview of formatted statements
No database connection required
Helpful for reviewing and sharing queries

Category: Editors

sql
query
format
database
editor

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Write and format SQL locally with a readable preview.

GraphQL Editor

Write and format GraphQL operations and fragments.

Free online GraphQL editor that validates and formats operations locally. Clean up queries, mutations, and fragments with GraphQL’s own parser and printer.

What you can do

Parse and format GraphQL documents
Catch syntax errors before you hit an API
Works with queries, mutations, and fragments
Runs entirely in the browser

Category: Editors

graphql
query
mutation
fragment
format

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Write and format GraphQL operations and fragments.

Environment Editor

Edit .env files with a redacted key/value preview.

Free online .env editor with a redacted key/value preview. Edit environment files safely while sensitive values stay masked in the preview pane.

What you can do

Key/value table preview with redacted secrets
Edit dotenv-style configuration locally
Reduce accidental secret exposure while reviewing
No upload of environment files

Category: Editors

env
dotenv
config
secrets
ini

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit .env files with a redacted key/value preview.

SVG Editor

Edit SVG markup with a sandboxed live preview.

Free online SVG editor with a sandboxed live preview. Tweak vector markup and see the graphic update instantly without uploading artwork.

What you can do

Live sandboxed SVG preview
Validate markup as you edit
Split editor and preview layouts
Ideal for icons and simple illustrations

Category: Editors

svg
vector
xml
preview
image

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Edit SVG markup with a sandboxed live preview.

Diff / Patch Editor

Inspect unified diffs and patches with line highlighting.

Free online unified diff and patch viewer with line highlighting. Paste git diffs to review additions and deletions with clear color cues — all locally in your browser.

What you can do

Unified diff syntax highlighting
Quick review of patches and pull-request hunks
Handles large diffs with sensible line limits
Private local inspection

Category: Editors

diff
patch
git
unified
editor

DevKit runs in your browser. No login, no paywall, and nothing is uploaded to a server.

Inspect unified diffs and patches with line highlighting.

Pick an editor or tool from the sidebar to get started.