Small tools. Zero friction.
Text and developer utilities that just work — no sign-up, no server round-trip, nothing ever leaves your device.
- 100free tools
- 100%private
- $0cost, always
- Word Counter Live word, character and reading-time stats.
- Case Converter UPPER, lower, Title, camelCase, snake_case and more.
- Lorem Ipsum Generator Placeholder text by words, sentences or paragraphs.
- Diff Checker Line-by-line diff of two text blocks via LCS.
- Text Cleaner Trim, collapse blanks, dedupe and sort lines of text.
- Regex Tester Test JavaScript regular expressions against your own text — matches, indices and capture groups.
- Markdown Previewer Live preview of a small Markdown subset — headings, bold, italic, code, links and lists.
- Slug Generator Turn any text into a lowercase, URL-safe slug — accents stripped, punctuation collapsed.
- Unicode Code Point Inspector Per-character code point, U+ hex value and UTF-8 byte length, including emoji outside the BMP.
- Word Frequency Analyzer Case-insensitive word counts, ranked most to least common.
- Regex Cheat Sheet Browsable reference of common regex patterns and syntax.
- Readability Score Calculator Flesch-Kincaid reading ease and grade level of your text.
- Text Truncator / Excerpt Generator Truncate text to a length at a word boundary, with an ellipsis.
- Find and Replace (Regex) Replace every regex match in text with a replacement pattern.
- JSON Formatter Pretty-print, minify and validate JSON.
- Base64 Encoder / Decoder Encode or decode Base64 with Unicode support.
- XML Formatter Pretty-print and validate XML, with clear errors on mismatched tags.
- JSON Path Evaluator Pull a value out of JSON with a simple dot/bracket path.
- CSS Beautifier / Minifier Beautify or minify CSS — string- and comment-aware.
- SQL Formatter Beautify SQL by keyword — SELECT, FROM, WHERE, JOIN and more.
- HTML Formatter Indent nested HTML tags, with void elements handled correctly.
- YAML ⇄ JSON Converter Convert YAML to JSON or JSON back to YAML.
- SVG Formatter / Minifier Pretty-print or minify SVG markup.
- JSON to TypeScript Converter Generate a TypeScript interface from a JSON sample.
- JSON Diff Checker Structural differences between two JSON documents.
- INI / Properties File Parser Convert INI or .properties key=value files to JSON and back.
- GraphQL Query Formatter Pretty-print a GraphQL query or mutation.
- .env File Parser Convert a .env file to JSON and back, comments and quotes intact.
- CSV Diff Checker Row-by-row and cell-by-cell differences between two CSV files.
- URL Encoder / Decoder Percent-encode or decode URLs and query strings.
- HTML Entity Encoder / Decoder Escape or unescape HTML entities like & and <.
- Base32 Encoder / Decoder Encode or decode RFC 4648 Base32 text.
- Hex ⇄ Text Converter Convert text to hexadecimal bytes and back.
- Binary ⇄ Text Converter Convert text to binary bytes and back.
- CSV ⇄ JSON Converter Convert CSV to JSON or JSON back to CSV, with proper quoted-field handling.
- Query String Parser & Builder Split a query string into key/value pairs, or build one from pairs.
- String Escape / Unescape Escape or unescape strings for JSON/JS literals or regex patterns.
- Punycode / IDN Converter Convert a domain name between Unicode and Punycode.
- File to Base64 Converter Convert any local file to a Base64 data URI.
- ROT13 / Caesar Cipher Shift letters by any amount — ROT13 and beyond.
- Morse Code Translator Convert text to Morse code and back.
- Base58 Encoder / Decoder Encode or decode Base58, the Bitcoin-address alphabet.
- Hash Generator Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes.
- HMAC Generator Generate keyed HMAC signatures with SHA-256/384/512.
- JWT Decoder Decode a JWT header and payload — no signature verification.
- Password Strength Checker Estimate password entropy and flag common weaknesses.
- Credit Card Number Validator Check a card number against the Luhn checksum.
- IBAN Validator Check an IBAN's shape and mod-97 checksum.
- JWT Encoder Build and sign a JWT with a header and payload.
- Basic Auth Header Encoder / Decoder Build or decode an HTTP Basic Authorization header.
- CRC32 Checksum Calculator Compute the CRC32 checksum of text or a file.
- Password Policy Checker Check a password against configurable length and character rules.
- URL Parser Break a URL into protocol, host, port, path, query and hash.
- User-Agent Parser Best-effort browser, OS and device type from a UA string.
- HTTP Status Code Reference Browsable table of HTTP status codes with lookup.
- CIDR / Subnet Calculator Network, broadcast, mask and usable host range from CIDR.
- IP Address Converter Convert IPv4 between decimal, integer, binary and hex.
- MAC Address Formatter Reformat a MAC address between colon, dash, dot and none.
- HTTP Header Parser Parse raw HTTP headers into a readable table.
- Sitemap Validator Check an XML sitemap against the sitemap protocol.
- DNS Record Type Reference Browsable reference of DNS record types and what each is for.
- User-Agent String Builder Build a realistic User-Agent string from browser, OS and device.
- MIME Type Lookup Look up the MIME type for a file extension, or the reverse.
- Bitwise Operations Calculator AND, OR, XOR, NOT, and bit shifts with binary display.
- Two's Complement Calculator Convert signed integers to two's complement binary and back.
- IEEE 754 Float Converter Convert decimals to IEEE 754 single/double-precision bits and back.
- ASCII Table Reference Full 7-bit ASCII table with character, hex, and control-code lookup.
- Levenshtein Distance Calculator Edit distance and similarity percentage between two strings.
- Number Formatter Add thousands separators or convert number formats.
- Prime Number Checker Check primality and list prime factors.
- GCD / LCM Calculator Greatest common divisor and least common multiple.
- Big-O Complexity Reference Browsable reference of common time-complexity classes.
- Matrix Calculator Add, multiply or find the determinant of small matrices.
- Combinatorics Calculator Permutations (nPr) and combinations (nCr) of n items.
- Color Converter Convert colors between HEX, RGB, HSL and CMYK.
- Color Contrast Checker Check WCAG AA/AAA contrast ratio between two colors.
- Color Shade Generator Generate a shade and tint ramp from any color.
- CSS Gradient Generator Build linear and radial CSS gradients from color stops.
- Color Palette Generator Complementary, triadic and analogous color schemes.
- CSS Box-Shadow Generator Build a CSS box-shadow with a live preview.
- CSS Clamp() Fluid Typography Calculator A responsive clamp() font-size from a min and max size.
- Color Blindness Simulator See how a color looks under common color vision deficiencies.
- Timestamp / Epoch Converter Convert Unix epoch seconds or milliseconds to a date, or a date to an epoch value.
- Date Format Converter Reformat a date using YYYY, MM, DD, HH, mm, ss tokens — always in UTC.
- ISO 8601 Duration Parser Parse a PnYnMnDTnHnMnS duration into years, months, days, hours, minutes and seconds.
- Cron Expression Parser & Explainer Parse a 5-field cron expression into plain English and see its next run times.
- Date Add / Subtract Calculator Add or subtract days, months or years from a date.
- Business Days Calculator Weekdays between two dates, weekends excluded.
- Meeting Time Overlap Finder Overlapping working hours across two or more time zones.
- Relative Time Formatter Format a timestamp as "3 hours ago" or "in 2 days".
- UUID / GUID Generator Random version-4 UUIDs, or the fixed nil UUID.
- ULID Generator Sortable, timestamp-prefixed unique IDs.
- Random String / Token Generator Alphanumeric, hex, base64url or numeric tokens of any length.
- Meta Tag & Open Graph Generator Title, description, Open Graph and Twitter Card tags.
- Fake Data Generator Mock rows of names, emails, phone numbers and IDs.
- Placeholder Image Generator An SVG placeholder image at any size, as a data URI.
- Cron Expression Builder Build a cron expression from a simple schedule.
- Markdown Table Generator Turn pasted CSV or tab-delimited data into a Markdown table.
- .gitignore Generator Assemble a .gitignore from common language and editor templates.
- License Text Generator Full open-source license text — MIT, Apache-2.0, GPL-3.0 and more.
Why DevKit
Everyday developer utilities — formatting, encoding, converting and inspecting text — that run in the browser with nothing to install.
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For everyday work
The small conversions and inspections you reach for constantly, in one place.
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Runs in your browser
Paste in whatever you are debugging. It is processed locally and never sent anywhere.
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No install, no account
Open the page and use it. Nothing to sign up for and nothing to keep updated.
Frequently asked questions
Is DevKit free?
Yes, and there is no account or sign-up at any point.
Is it safe to paste sensitive data — API keys, tokens, real JSON payloads?
Everything is processed in your browser with JavaScript. Whatever you paste is never sent to a server, so it stays on your machine.
Do I need to install anything?
No. It runs entirely in the browser tab — nothing to install, nothing to keep updated.