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Dev & Data tools
31 free dev & data tools — private and offline.
CSV Query
filter, sort and pick columns from pasted CSV
CSV Merge & De-duplicate
remove duplicate rows, by key or whole row
CSV Column Summary
row counts, blanks, distinct values and number stats
CSV Chart (SVG)
turn a column of numbers into a bar chart
CSV Report Builder
turn a CSV into a titled, aligned, printable report
Data Dashboard Builder
turn a CSV into KPI cards and charts you can save and share
Spreadsheet Lite (formula evaluator)
evaluate spreadsheet formulas over a pasted CSV grid
SQL Playground
run real SQL over a pasted CSV — entirely in your browser
Survey Builder & Results Tally
write a survey, print it, then tally the answers you get back
JSON Formatter
pretty-print or minify + validate
Base64 Encode
text → base64
Base64 Decode
base64 → text
URL Encode
percent-encode a string
URL Decode
decode percent-encoding
HTML Encode
escape HTML entities
HTML Decode
unescape HTML entities
JSON → CSV
array of objects → CSV
CSV → JSON
CSV → array of objects
JWT Decode
decode header + payload (no verify)
SHA-256
hash text with SHA-256
Query String Parser
?a=1&b=2 → readable list
Timestamp → Date
Unix epoch → readable date
Date → Timestamp
date → Unix epoch
Regex Tester
test a pattern against text
Text Diff
line-by-line difference of two texts
HTTP Status Lookup
what a status code means
Luhn / Card Check
validate a card number checksum
Markdown → HTML
basic markdown to HTML
UTM Link Builder
add campaign tags to a URL
Password Strength
estimate how strong a password is
Bulk Rename & Index Planner
plan a bulk rename + index, offline — nothing is renamed