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Use developer tools for fast technical checks without opening a heavyweight app. The goal is simple: make encoding, formatting, subnetting, passwords, URLs, and debugging helpers easy to run in the browser with clear privacy notes.
Browse and filter developer toolsAll developer utilities
Choose a tool for your task. Open its matching guide when you need the inputs or results explained.
Subnet CalculatorCalculate IPv4 CIDR network, broadcast, mask, wildcard, and usable host range.Password GeneratorGenerate strong random passwords with length, character sets, and ambiguity controls.Base64 Encode / DecodeEncode UTF-8 text to Base64 or decode Base64 back to text.URL Encode / DecodePercent-encode URL component text or decode percent-encoded text.Bandwidth CalculatorEstimate file transfer time from data size and network bandwidth.JSON FormatterFormat and validate JSON with two-space indentation and optional sorted object keys.
Browse all 17 developer tools
The 6 choices above and these 11 tools make up this category.
- JSON to CSV ConverterConvert JSON objects or arrays to CSV with nested fields, a table preview, and spreadsheet-safe output.
- UUID GeneratorGenerate UUID v4 identifiers with quantity, uppercase, and hyphen options.
- Hash GeneratorGenerate SHA-256, SHA-384, or SHA-512 text digests in hexadecimal format.
- UTM BuilderBuild campaign URLs with source, medium, campaign, content, and term parameters.
- Query String ParserParse URL query strings into JSON or build encoded query strings from key-value lines.
- HTML Entity Encoder / DecoderEncode HTML-sensitive characters or decode common named and numeric HTML entities.
- CSS Clamp CalculatorGenerate CSS clamp formulas for fluid font sizes, spacing, and responsive layout values.
- API Pricing CalculatorEstimate API usage cost from request count, units per request, unit price, fees, and overhead.
- Download Time CalculatorEstimate how long a file, game, backup, or update will take to download.
- Internet Speed Needs CalculatorEstimate a household or workspace internet speed need from simultaneous activities.
- Streaming Bitrate CalculatorEstimate stream or recording data use from bitrate, time, and stream count.
Help choosing a tool and checking its results
Fast technical checks in the browser
Developer tools should be copy-friendly, private by default, and clear about security assumptions. They are useful for routine checks, not a substitute for production review.
I need network rangesCalculate CIDR ranges, usable hosts, masks, broadcast addresses, and network blocks.I need a passwordGenerate strong random passwords and review length, symbols, and storage advice.I need URL encodingPercent-encode or decode URL component text without sending it away.I need readable JSONFormat, validate, and copy JSON while keeping the source text in the browser.I need campaign URLsBuild UTM links with clear source, medium, campaign, term, and content fields.I need an API or MCP endpointInspect deterministic tool schemas, REST endpoints, and the stateless MCP connection for approved developer clients.
guides available
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Developer checks to open first
These utilities cover common interface and documentation jobs, including color contrast and Markdown table formatting.
What this category helps with
- Technical browser utilities for subnetting, passwords, encoding-style tasks, and developer checks.
- Local-first tools that avoid sending sensitive technical inputs to a server.
- Research-backed notes for standards-sensitive workflows such as CIDR and password generation.
Guides for this category
Each guide uses its matching tool, with example numbers and plain limits.
- How to use the Subnet CalculatorLearn how IPv4 CIDR subnet math finds network, mask, broadcast, and usable range. Includes input tips, examples, result checks, and unit or mode notes for t...
- How to use the Password GeneratorLearn how to generate strong unique passwords safely in the browser. Includes input tips, examples, result checks, and unit or mode notes for the Password G...
- Base64 Encode / Decode GuideUse the Base64 Encode / Decode guide to encode UTF-8 text, decode Base64, check padding, troubleshoot invalid input, and avoid treating Base64 as encryption.
- How to Use the URL Encode / Decode ToolUse the URL Encode / Decode guide to encode query values, decode percent-encoded text, compare %20 with plus spaces, and avoid whole-URL mistakes.
- How to use the Bandwidth CalculatorLearn how file size, bandwidth, and bits-versus-bytes math estimate download or upload time. Includes input tips, examples, result checks, and unit or mode...
- How to use the JSON FormatterLearn how to format, validate, sort, and copy JSON in the browser. Includes input tips, examples, result checks, and unit or mode notes for the JSON Formatter.
Browse all 17 guides in this category
- How to Convert JSON to CSV SafelyConvert JSON to CSV safely with nested dot-notation columns, CSV quoting, array handling, formula protection, UTF-8 notes, and a worked example.
- How to use the UUID GeneratorLearn how to generate UUID v4 identifiers locally in the browser. Includes input tips, examples, result checks, and unit or mode notes for the UUID Generator.
- Hash Generator GuideUse the Hash Generator guide to choose SHA-256, SHA-384, or SHA-512, generate a browser-side text digest, and avoid password/authenticity mistakes.
- UTM Builder GuideUse the UTM Builder guide to create campaign URLs, choose source, medium, and campaign labels, preserve query values, and avoid messy reports.
- Query String Parser GuideUse the Query String Parser guide to parse URL parameters, group repeated keys, build encoded query strings, and avoid private-token mistakes.
- HTML Entity Encoder / Decoder GuideUse the HTML Entity Encoder / Decoder guide to escape HTML snippets, decode named or numeric entities, read entity counts, and avoid sanitizer mistakes.
- CSS Clamp Calculator GuideUse the CSS Clamp Calculator guide to enter min/max sizes, viewport range, and root font size, then copy and check a fluid clamp() formula.
- API Pricing Calculator GuideUse the API Pricing Calculator guide to estimate request cost, billable units, fixed fees, retry overhead, total API spend, and average cost per request.
- Download Time Calculator GuideUse the Download Time Calculator guide to estimate file transfer time from KB, MB, GB, or TB size, Mbps speed, and a realistic efficiency percent.
- Internet Speed Needs Calculator GuideUse the Internet Speed Needs Calculator guide to estimate household Mbps from simultaneous streams, gaming, video calls, smart devices, and buffer percent.
- Streaming Bitrate Calculator GuideUse the Streaming Bitrate Calculator guide to estimate stream or recording data use from bitrate, duration, stream count, MB, GB, and variable-bitrate limits.