Dev & Tech
Dev & tech tools handle the small, repetitive jobs in coding and design: color and unit conversion, encoding, formatting, ID generation, and base math, for developers, designers, and students.
Free aspect ratio calculator: enter original width and height plus a new width or height, and it solves the missing dimension and shows the simplified ratio like 16:9.
Free Base64 decode and encode tool. Convert text to Base64 or decode Base64 to text instantly, UTF-8 safe, in your browser. Nothing is uploaded.
Free binary translator to convert text to binary and binary to text instantly. Each character becomes 8-bit ASCII binary, decoded back to readable text in your browser.
Free color contrast checker that computes the WCAG contrast ratio between text and background, from 1:1 to 21:1, and shows AA and AAA pass or fail.
Find the name of any color. Pick or paste a HEX code and the color name finder returns the closest named color with its swatch and code. Free online color identifier.
Build a valid cron expression with presets or custom fields, and read it back in plain English. Covers minute, hour, day, month and weekday with * , - / syntax.
Create CSS gradients visually and copy the code. Pick two colors, choose linear or radial, set the angle, and get ready-to-use CSS. Free online gradient maker.
Convert px to rem and rem to px for CSS, with any root font size. Live two-way conversion plus the ready-to-paste CSS value and the exact formula shown.
Free px to rem converter for CSS. Convert between px, rem, em and pt at any root font size and see all four units at once, instantly in your browser.
Free DPI calculator: enter resolution and screen size to find pixel density (PPI/DPI), dot pitch and physical screen dimensions instantly with the formula shown.
Check if an email address is valid. Paste one or many addresses to validate format, spot common typos like gmail.con, and see why an email is invalid. Free and private.
Pick any color and get its HEX, RGB and HSL codes instantly, or type a HEX to preview it. Free online hex color picker for designers and developers. Copy with one tap.
Convert a hex color code to RGB instantly, and edit R, G, B back to hex. See live HSL values and a color swatch for any hex to rgb conversion in your browser.
Free IPv4 subnet calculator. Enter an IP and CIDR prefix to get the network address, broadcast, subnet mask, wildcard mask, usable host range, and host count.
Validate JSON online and find errors with the exact line and column. Format or minify valid JSON and copy the result. Free, private JSON validator and checker.
Free JSON formatter, beautifier and validator. Pretty-print JSON with 2-space indentation or minify it instantly in your browser. Nothing is uploaded.
Generate an MD5 hash from any text instantly and privately in your browser. Get the 32-character hex digest with one-click copy. Nothing is uploaded.
Free Morse code translator to convert text to Morse code and Morse code to text instantly. Uses the International Morse alphabet, letters, digits and punctuation, in your browser.
Free number base converter to convert between binary, octal, decimal and hexadecimal instantly. Pick a source base, enter a value, and see all four bases in your browser.
Check how strong your password is with a private, in-browser entropy estimate. See strength, entropy bits, and tips to make it harder to crack. Nothing is sent.
Calculate the minimum PCB trace width for a given current using the IPC-2221 standard. Enter amps, temperature rise, copper weight and layer for an instant result.
Generate random colors instantly with HEX, RGB and HSL values you can copy. Make a palette of up to 24 colors at once. Free tool for designers and developers.
Test JavaScript regular expressions online. Enter a pattern, flags, and a test string to see live matches, positions, and capture groups instantly in your browser.
Convert RGB to HEX instantly with live sliders and a preview, or paste a HEX to load RGB. Free online RGB to hex color converter for designers and developers.
Convert any RGB color to CMYK percentages instantly. Enter R, G and B values from 0 to 255 and see Cyan, Magenta, Yellow and Key with the formula and a live swatch.
Convert a Unix timestamp to a human date and back. Supports seconds and milliseconds, shows UTC, local time, ISO 8601 and a relative 'time ago' value.
Free online URL encoder and decoder. Percent-encode text for safe URLs with encodeURIComponent or decode it back instantly, in your browser. Nothing uploaded.
Free UUID generator: create cryptographically secure version-4 (random) UUIDs online, one or up to 100 at a time, with an optional uppercase toggle. Runs in your browser.
Calculate video file size from bitrate and duration, or the bitrate needed to hit a target file size. Includes the audio track and shows the full formula and steps.
Instantly see your public IP address, plus your browser language, platform and screen size. Free what is my IP tool. Your IP is fetched live and never stored.
What are dev & tech tools?
Dev & tech tools are free online utilities that automate small, fiddly tasks in coding and design, such as converting color and CSS unit formats, formatting JSON, encoding text or URLs, generating unique identifiers, and converting number bases. Developers, designers, students, and hobbyists use them to skip manual lookups and avoid copy-paste mistakes.
Dev & Tech tools on Toolzent
Pick the tool that matches the job you are doing right now.
| Tool | What it does |
|---|---|
| Hex to RGB Converter | Converts a hex color code to RGB and HSL values with a live swatch, and works in reverse too. |
| Base64 Encode and Decode | Encodes text to Base64 or decodes Base64 back to text, UTF-8 safe, in one click. |
| UUID Generator | Generates random version 4 UUIDs in bulk, with an optional uppercase format and copy-all button. |
| Aspect Ratio Calculator | Solves a missing width or height to keep an image or video at the same aspect ratio. |
| Binary Translator | Translates plain text into 8-bit binary and converts space-separated binary back to readable text. |
| JSON Formatter | Pretty-prints, indents, and validates JSON, flagging syntax errors so payloads stay readable. |
| URL Encoder / Decoder | Percent-encodes text for safe use in query strings and decodes encoded URLs back to plain text. |
| Color Contrast Checker | Calculates the contrast ratio between two colors and checks it against WCAG AA and AAA levels. |
| Number Base Converter | Converts a number between binary, octal, decimal, and hexadecimal in one step. |
| Morse Code Translator | Converts text to Morse code dots and dashes, and decodes Morse back into readable letters. |
| CSS Unit Converter | Converts between px, rem, em, and percent based on a chosen root font size. |
Common dev & tech formats and examples
These reference values show what each tool produces, so you know what to expect.
| Task | Example input | Example output |
|---|---|---|
| Hex to RGB | #8b5cf6 | rgb(139, 92, 246) |
| Base64 encode | Man | TWFu |
| Binary encode | Hi | 01001000 01101001 |
| URL encode | a b&c | a%20b%26c |
| Decimal to hex | 255 | ff |
| px to rem at 16px root | 24px | 1.5rem |
A three-digit hex like #abc expands to #aabbcc before conversion. Base64 and binary are reversible, so decoding TWFu returns Man. URL encoding swaps unsafe characters for percent codes, so a space becomes %20, and CSS unit math is anchored to a root font size, so at a 16px root, 24px equals 1.5rem.
How do I choose the right tool?
Match the tool to what you are working on:
- Picking a UI color? Use the Hex to RGB Converter to move between hex, RGB, and HSL, then confirm legibility with the Color Contrast Checker.
- Moving text through a JSON field, header, or email body? Reach for Base64 Encode and Decode, and use the URL Encoder / Decoder for query strings.
- Debugging an API response? The JSON Formatter pretty-prints and validates the payload so errors stand out.
- Need unique keys for a database or test data? Generate them with the UUID Generator.
- Working with bits and bases? The Binary Translator maps characters to bits, and the Number Base Converter switches between binary, octal, decimal, and hex.
- Sizing layouts or media? Use the CSS Unit Converter for px, rem, and em, and the Aspect Ratio Calculator to scale images and video without distortion.
- Encoding a message for fun? The Morse Code Translator converts text to dots and dashes and back.
If you are unsure, start from your input format: a color code points to the hex converter, a string of zeros and ones to the binary translator, and a width needing a matching height to the aspect ratio tool.
Why use Toolzent’s dev & tech tools?
Toolzent’s dev & tech tools are 100% free with no sign-up and nothing to install. They run privately in your browser, so the text, colors, JSON, and IDs you work with stay on your device and are never uploaded. Results appear instantly, and each tool follows the same standards used everywhere else, so a hex code, a Base64 string, or a UUID produced here behaves exactly like one from your code editor.
For related work, explore our Unit Converters, Math & Algebra, and Text & Writing category hubs.
Frequently asked questions
Are these dev & tech tools free to use?+
Yes. Every dev and tech tool on Toolzent is 100% free with no account, no trial, and no usage limits.
Do I need to sign up or install anything?+
No. The tools run entirely in your browser, so there is nothing to install and no login to remember.
Is my data private when I format JSON or generate UUIDs?+
Yes. Formatting, encoding, decoding, and ID generation all run locally in your browser, so the text and values you enter are never uploaded or stored.
What is the difference between hex, RGB, and HSL color formats?+
Hex is a six-digit code like #8b5cf6, RGB lists red, green, and blue from 0 to 255, and HSL uses hue, saturation, and lightness; the Hex to RGB Converter shows all three at once.
Is Base64 a form of encryption?+
No. Base64 is reversible encoding, not encryption, so anyone can decode it. Use it to move text or binary safely through text-only channels, not to keep data secret.
What does the Color Contrast Checker measure?+
It measures the contrast ratio between a text color and its background and reports whether the pair meets WCAG AA and AAA accessibility thresholds.