76 tools· 6 languages· 0 trackers

Built for the people
who build the web.

Free tools for HAR, DNS, HTTP, email auth, CSP and the everyday — running in your browser, not on our servers.

popular base64 jwt-decoder dns-lookup har-viewer regex-tester csp-generator

§01 focus areas

deep coverage, not just widgets

Where sitekits goes deep.

01 HAR waterfall · timings · verdicts 02 tools → 02 DNS records · propagation · rDNS 01 tools → 03 HTTP headers · redirects · status 09 tools → 04 Email SPF · DKIM · DMARC 03 tools → 05 CSP evaluate · build · report 01 tools → 06 Security hashes · certs · JWT 11 tools → 07 SRE cron · uptime · error budgets 03 tools → 08 Privacy local by design 68/76 local

§02 all tools

76 live · grouped by tag · press ⌘K

Every tool, one keystroke away.

format & convert 30

Markdown Preview local JSON Formatter / Validator local XML Formatter local SQL Formatter local HTML Formatter local CSS Formatter local JavaScript Formatter local + 23 more →

encode & decode 10

Base64 Encode / Decode local URL Encode / Decode local Hash Generator local HTML Entity Encoder & Decoder local JavaScript Hex String Escape local XML String Escaper local Number Base Converter local + 3 more →

generate 09

Password Generator local UUID v4 Generator local Content Security Policy Generator local CSV to SQL Converter local JSON to TypeScript Interface Generator local Crontab Expression Editor local Random JSON Data Generator local + 2 more →

validate & inspect 38

JSON Formatter / Validator local XML to XSD Schema Generator local Regular Expression Tester local XPath Expression Tester local YAML Validator local HTML Validator local JavaScript Syntax Validator local + 31 more →

network 23

IP Address Checker server DNS Lookup Tool server HTTP Headers Checker server IPv4 Subnet Calculator local IPv6 Subnet Calculator local IPv4 Address Converter local IPv6 Address Compressor local + 16 more →

security & email 16

HTTP Security Header Checker server Hash Generator local Password Generator local HTML Entity Encoder & Decoder local XML String Escaper local UUID v4 Generator local Content Security Policy Generator local + 9 more →

text 14

URL Encode / Decode local HTML Entity Encoder & Decoder local JavaScript Hex String Escape local XML String Escaper local Markdown Preview local Text Diff Checker local Regular Expression Tester local + 7 more →

time & image 12

Download Time Calculator local Unix Time Converter local Timezone Converter local Crontab Expression Editor local SLA Uptime Calculator local Error Budget Calculator local ICS Calendar Viewer local + 5 more →

Browse all 71 tools 18 tags · 8 focus hubs · 6 languages

§03 privacy model

Designed with privacy in mind.

sitekits is built local-first. Paste anything sensitive — tokens, headers, configs — and it is parsed right here in your browser. Not logged, not stored, not seen.

local: 68; No network requests. Input is processed in your browser and never sent.
server: 7; ip-check · dns-lookup · http-headers — answered by our API, never stored.
external: 1; rest-api-tester calls your target directly. It never touches our servers.