AI-readable site index

Published tools

• JSON Minifier

  JSON Minifier runs JSON.parse and then JSON.stringify. That validates standard JSON and removes layout whitespace, but it is not a byte-preserving transform: duplicate keys keep the last value, large or non-finite numeric results can change, negative zero becomes zero, and integer-like object keys can be reordered.

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• JWT Decoder

  JWT decoding only turns the Base64URL Header and Payload into readable JSON. It does not prove the token is authentic, unchanged, unexpired, or authorized. Important systems must verify the signature and validate claims on the server with trusted keys.

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• Day of Year Calculator

  The Day of Year Calculator compares the selected date with January 1 of the same year, returns a 1-based day-of-year number, and shows whether the year has 365 or 366 days.

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• Leap Year Checker

  A Gregorian leap year is divisible by 400, or divisible by 4 but not by 100. Leap years have 366 days and February has 29 days; common years have 365 days and February has 28 days.

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• Date Format Converter

  Date format conversion should start by confirming the source format. Auto-detect only accepts unambiguous year-first values; MM/DD/YYYY and DD/MM/YYYY must be selected explicitly so 01/02/2026 is not silently interpreted the wrong way.

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• Batch Timestamp Converter

  For batch Unix timestamp conversion, enter one integer per line, choose auto-detect or force seconds/milliseconds, and select the output format. Auto mode treats 10 digits or fewer as seconds and 11 digits or more as milliseconds after removing a leading minus sign.

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• Working Hours Calculator

  A working hours calculator subtracts start time from end time, deducts break minutes, and returns gross minutes, net working minutes, decimal hours, and an hours-minutes breakdown. Overnight shifts must be enabled explicitly, and the result is a calculation aid, not labor-law or payroll guidance.

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• Fraction Calculator

  A fraction calculator combines two fractions with addition, subtraction, multiplication, or division, then reduces the result by the greatest common divisor. This tool also simplifies a single fraction and displays an improper fraction, mixed number, and decimal approximation.

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• Exponent Calculator

  An exponent calculator raises a base to a selected power, such as 2^10, 5^-2, or 9^0.5. Negative exponents are treated as reciprocals, zero to a negative exponent is rejected, and negative bases only support integer exponents because decimal exponents may require complex-number interpretation.

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• Text Diff Checker

  Text Diff Checker shows added, removed, and unchanged lines or words between two pasted text snippets. It is useful for copy, FAQ, config snippets, emails, and release-note drafts, with browser-local processing and manual review.

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• Text Reverser

  Text Reverser reverses pasted text locally by lines, words, or characters. Line reversal changes the order of lines, word reversal changes the order of non-whitespace word chunks while preserving separators, and character reversal uses browser grapheme segmentation when available so emoji and combining marks are handled more safely than simple byte reversal.

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• List Randomizer

  List Randomizer treats each line as one list item and shuffles the order locally with browser randomness. It is useful for everyday ordering, practice sets, draft rotations, and test sample shuffling; it is not appropriate for regulated lotteries, prize drawings, security decisions, or any workflow that needs auditable randomness.

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• XML Formatter

  XML Formatter checks whether the input is well-formed before producing a two-space indented result. XML minifying removes layout whitespace between tags. It does not validate DTD, XML Schema, namespace semantics, or API-specific rules, so important XML should still be reviewed against the target system.

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• YAML Formatter

  YAML Formatter parses the input first, then prints a two-space indented YAML result or a validation summary. It is useful for reviewing configs, front matter, and workflow files, but it does not verify application-specific schema, secrets, deployment safety, or vendor rules.

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• TOML Formatter

  TOML Formatter cleans common TOML layout issues and reports obvious syntax boundaries such as unclosed quotes, arrays, tables, or missing key-value separators. It is useful for reviewing readable config snippets, but it does not prove that Cargo, Python, Hugo, Taplo, or any other tool will accept every schema-specific field.

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• CSV to JSON Converter

  CSV to JSON conversion turns each data row into an object and uses the first CSV row as field names. This tool keeps values as strings, supports common quoted CSV fields, and runs in the browser. Review headers, row counts, extra columns, and target API rules before importing the result.

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• JSON to CSV Converter

  JSON to CSV conversion works best for one object or an array of similarly shaped objects. This tool builds the header from all object keys, escapes CSV cells, keeps nested JSON reviewable as strings, and runs entirely in the browser.

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• Query String Parser

  The Query String Parser reads the part after ?, splits key-value pairs on &, decodes percent encoding and plus-as-space query syntax, and preserves repeated keys in order. Repeated keys are not overwritten; grouped JSON stores them as arrays.

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• HTTP Status Code Reference

  The HTTP Status Code Reference maps common 1xx, 2xx, 3xx, 4xx, and 5xx responses to plain-language meanings and debugging notes. It is a static browser-local reference, not a network diagnostic or uptime checker.

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• Cron Expression Parser

  The Cron Expression Parser supports five-field Unix cron plus common @hourly, @daily, @weekly, @monthly, and @yearly macros. It explains the dialect, timezone mode, day-of-month versus weekday OR semantics, and previews a limited number of future runs within a 366-day window. Quartz seconds, year fields, and provider-specific syntax are outside scope.

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• Regex Tester

  The Regex Tester uses browser JavaScript RegExp semantics. It supports g, i, m, s, u, and y flags, shows up to 100 matches, lists capture groups, and previews JavaScript replacement output. Use it for text extraction, log filters, and frontend validation drafts, not as a substitute for code review, performance testing, or another language's regex engine.

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• Markdown Table Generator

  The Markdown Table Generator converts delimited text into a GitHub-flavored Markdown table, pads short rows, builds the separator row, and escapes cell pipes as \|. The first row can become the header, or the tool can generate Column 1 style headers. Alignment is expressed with ---, :---, :---:, or ---: markers.

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• HTML Minifier

  HTML minifying can shorten tags, attributes, layout whitespace between tags, and ordinary comments, but it should not blindly rewrite text nodes, script, style, pre, or textarea content. This tool uses a conservative strategy: it preserves those sensitive areas, removes ordinary comments, and keeps conditional or bang-preserved comments to avoid accidental semantic changes.

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• CSS Minifier

  A CSS Minifier should remove only layout whitespace and ordinary comments that do not change CSS meaning. This tool uses a conservative strategy: it preserves strings, url() content, spaces around calc() plus and minus operators, custom-property values, and /*! protected comments, while checking comments, quotes, brackets, parentheses, and braces before returning output.

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• JavaScript Beautifier

  JavaScript Beautifier turns compact scripts into a two-space indented reading draft and checks comments, quotes, template literals, regex literals, and brackets before returning output. It does not run code, load dependencies, parse source maps, minify code, or prove business logic is correct.

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• URL Parser

  The URL Parser uses standard URL syntax to split scheme, origin, username, password, host, hostname, port, path, query string, fragment, and query parameters. It is useful for debugging link structure, but it does not send network requests, verify that a page exists, or decide whether a domain is trustworthy.

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• JSONPath Tester

  JSONPath Tester supports the $ root, dot properties, bracket properties, array indexes, wildcards, recursive descent, and simple comparison filters such as ?(@.price < 10). It does not execute scripts, functions, arbitrary expressions, network requests, or non-local data access.

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• HMAC Generator

  HMAC Generator uses browser Web Crypto to calculate HMAC-SHA-256, HMAC-SHA-384, or HMAC-SHA-512 and returns hex or base64 output. Use test secrets or short-lived debugging secrets only; do not paste production keys, private keys, access tokens, seed phrases, or customer data into an uncontrolled page.

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• Cookie Parser

  Cookie Parser turns strings such as `name=value; other=123` into a reviewable local table, tries percent-decoding by default, and flags duplicate names, empty values, and decode failures. It does not read browser cookie storage, connect to external services, or replace security audits, privacy compliance, or consent management.

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• Checksum Calculator

  Checksum Calculator computes CRC-32, Adler-32, or an 8-bit byte sum from the UTF-8 bytes of your input and shows the hexadecimal value, decimal value, and byte count. Checksums mainly catch accidental errors. For tamper resistance, authentication, or stronger integrity, use a hash, HMAC, or the mechanism required by your protocol.

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• Password Strength Checker

  Password Strength Checker scores length and character variety, then deducts points for common passwords, repeated characters, simple sequences, and single-character-class values. It is a browser-local estimate, not proof that a password is secure, unique, or absent from breach data.

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• Robots.txt Tester

  Paste the proposed file, enter an exact crawler product token such as Googlebot, and test a path or complete HTTP URL. The result covers the pasted access rules only: it does not fetch the live file, interpret Sitemap or Crawl-delay, reproduce every crawler extension, or prove crawling or indexing.

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• Image Resizer

  Image Resizer redraws the originally selected static bitmap to a Canvas at the requested width and height. With the ratio lock on, changing 4000 × 3000 to 1200 pixels wide derives 900 pixels high. Every Generate action reads the original selection rather than the previous export, and a download appears only when the returned Blob MIME matches the requested PNG, JPEG, or WebP type.

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• Image Cropper

  Image Cropper samples a rectangle from the originally selected static bitmap. X and Y identify its top-left pixel; width and height define the output. For a centered square from 2400 × 1600, use X 400, Y 0, width 1600, and height 1600. The rectangle must stay inside the source, and the download extension is derived only after the returned Blob MIME matches the requested format.

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• Image Format Converter

  Image Format Converter decodes the originally selected static bitmap and re-encodes the same width and height as PNG, JPEG, or WebP. It does not merely rename the file. Each conversion starts from the source selection, not the previous preview; JPEG output is drawn over white in this implementation. If the browser falls back to another MIME, the tool reports the mismatch instead of giving the file a misleading extension.

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Published articles

• Browser-local Image Processing: Privacy Boundary and Test

  “Browser-local” is a narrow implementation statement about the selected image operation. It is not a claim that the whole page is offline, the device is trusted, the user is anonymous, or every source property is removed.

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• Choose JPEG, PNG, or WebP by Requirement

  A format label is not a complete outcome. The same source can produce different bytes, artifacts, transparency, and recipient behavior depending on the browser and settings.

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• Crop an Image to a Square with Exact Coordinates

  A square only requires equal width and height; a useful square also keeps the subject safe after an avatar, card, or marketplace applies its own mask.

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• Crop, Resize, or Convert: Choose the Image Operation

  Three image operations can all produce a new file, but they answer different requirements: what remains in frame, how many pixels are delivered, and how those pixels are encoded.

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• Image Pixel Dimensions and File Size Are Different

  Dimensions describe a rectangular grid; file size describes the bytes produced by one encoder for one image. They influence each other, but neither value predicts the other by itself.

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• Checklist Before Publishing Minified HTML

  Minifying HTML is not the same as being ready to publish. The compact result should be reviewed in the target page, email client, CMS, or template system.

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• Cron Job Debugging Checklist

  When a job misses, repeats, or runs at the wrong time, do not edit only the expression. Timezone, permissions, environment, and scheduler differences often cause the failure.

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• Five-Field Cron vs Quartz Cron

  Different schedulers can use different field counts and special characters while still calling the syntax cron. Confirm the dialect before copying an expression.

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• How to Avoid Catastrophic Regex Backtracking

  Catastrophic backtracking is usually visible only on a near-matching or failing input that forces the engine to revisit many paths. A short successful sample can hide it.

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• How to Read HTTP Status Codes During API Debugging

  A status code tells you how a server classified a request, but it rarely tells the whole story. The same 400, 401, 404, or 500 can have different causes across APIs, proxies, and deployment environments.

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• How to Test a Regular Expression

  A useful regex test has positive cases, counterexamples, exact match ranges, expected groups, and a stated target engine. One successful sample is not a specification.

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• Why HTML Minifying Should Not Rewrite script and style

  HTML, JavaScript, and CSS are different languages. A tool that understands markup can easily break code if it also rewrites script or style content with simple text rules.

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• How to Convert CSV to JSON Safely

  CSV is easy to export, but JSON imports usually need stable keys and predictable row objects. A careful conversion flow keeps the result reviewable before it reaches an API, script, or database import.

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• How to Handle Repeated Query Parameters

  Repeated Query parameters are common in multi-select filters, checkbox values, batch IDs, and accidental UTM concatenation. The tricky part is that backend libraries and frameworks do not all use the same default behavior.

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• How to Inspect URL Structure Without Opening a Link

  When reviewing an unfamiliar link or production callback URL, you may want to inspect the structure before opening the page. A URL Parser can help with that first step, but it is not a reputation service.

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• JSON Minify vs Format: What Is the Difference?

  The same JSON can be compacted into one line or expanded into an indented structure. Both operations should start by confirming that the input is valid JSON.

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• Query String Parsing vs URL Encoding

  Many URL debugging problems involve both structure and encoding: structure decides which parameters exist, while encoding decides how a value can safely appear in a URL. Mixing them up can encode an entire URL or miss special characters.

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• URL Parser vs Query String Parser

  URL debugging often involves both structure problems and parameter problems. Choosing whether to inspect the whole link or just the part after ? reduces false assumptions.

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• When Should You Minify JSON in an API Request Body?

  API request bodies often move from readable JSON into docs, terminals, gateway fields, and logs. Minifying can make copying easier, but it is not a substitute for checking the API contract.

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• Why a JSON Minifier Should Validate First

  Many minifying failures are not minifier failures. The input is often not standard JSON. Parsing first exposes syntax problems before compact output is generated.

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• XML Format vs Minify: What Is the Difference?

  The same XML can be expanded into an indented structure or compacted into shorter text. The right choice depends on whether you need human review or a compact snippet.

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• Build a Robots.txt Path Matrix Before Publishing

  A robots.txt review is more reliable when it starts with URLs and expected decisions, not with a visual scan of directives. Freeze the proposed text, list representative paths for each crawler product token, record the winning rule, and rerun the same matrix after every edit.

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• How to Extract URLs From a Sitemap

  A sitemap usually lists the URLs a site wants to expose for discovery. When you paste sitemap XML into an extractor, the most useful output is often a simple list of loc values that you can scan, compare, and audit.

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• Why Search Results Can Differ From a Meta Preview

  A meta preview is useful when you want to review a title, description, and URL before publishing. It can reveal obvious length, clarity, and wording problems. It cannot reproduce the live decision process of an external search result page.

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How tools and articles connect

Tool pages explain a practical browser-local task. Article pages add context, formulas, limits, and review checks. Related links only point to published same-locale tools, categories, and articles.

Each locale is governed independently. Counts and links on this page come from AI-readable page eligibility, not from the raw published source ledger.

Important notes

• Base64, URL encoding, and HTML entities are encodings, not encryption.
• Browser-local processing does not make sensitive input absolutely safe.
• Calculator, converter, date, commerce, SEO, and security utilities are practical aids, not professional advice or compliance decisions.
• Security and privacy tools do not replace password managers, key management, DLP, audits, or manual review.
• Do not infer that planned languages, tools, services, accounts, or backend features are published.