# AppHelp

> Free, privacy-first online utility tools for developers, writers, designers, and content workflows.

AppHelp is an online utility directory with browser-local tools for formatting, encoding, conversion, document, color, image, and text cleanup tasks. No account is required and tools are designed to avoid uploading user input by default.

## Canonical Routes

- [English home](https://apphelp.net/en): localized AppHelp directory and tool discovery page.
- [Guide index](https://apphelp.net/en/guides): explanatory guides for common utility decisions and format mistakes.
- [Sitemap index](https://apphelp.net/sitemap.xml): sitemap index for apphelp.net and public tool subdomains.
- [Home URL sitemap](https://apphelp.net/sitemap-home.xml): apphelp.net home, category, and guide URLs.
- [Legacy AI profile](https://apphelp.net/llm.txt): compact line-based AI retrieval profile.

## Category Hubs

- [Developer Tools for JSON, APIs, Encoding, and Debugging](https://apphelp.net/en/tools/developer): AppHelp developer tools run in the browser for fast JSON, API, encoding, hashing, JWT, cURL, GraphQL, SQL, XML, YAML, and request-inspection workflows without uploading input by default.
- [Data Conversion Tools for Time, Tables, Query Strings, and Files](https://apphelp.net/en/tools/data): AppHelp data tools help convert between common operational formats such as timestamps, query strings, JSON, CSV, Markdown tables, PDFs, and text-friendly encodings without requiring accounts or uploads by default.
- [Writing Tools for Markdown, Text Cleanup, and Documentation](https://apphelp.net/en/tools/writing): AppHelp writing tools support Markdown, README, changelog, meeting note, subtitle, text sorting, word counting, case conversion, and copy cleanup workflows directly in the browser.
- [Image, Color, and PDF Tools for Browser-Local Asset Work](https://apphelp.net/en/tools/image): AppHelp image tools cover compression, resizing, cropping, conversion, metadata removal, SVG export, QR codes, color conversion, social images, favicons, and PDF page workflows with local processing by default.

## Guides

- [Unix Timestamp Seconds vs Milliseconds](https://apphelp.net/en/guides/unix-timestamp-seconds-vs-milliseconds): Learn how to identify 10-digit Unix seconds, 13-digit Unix milliseconds, UTC ISO output, and common timestamp conversion mistakes.
- [JSON Escape vs JSON.stringify](https://apphelp.net/en/guides/json-escape-vs-stringify): Understand the difference between escaping JSON string content, formatting a JSON document, and using JSON.stringify in JavaScript.
- [Base64 Is Encoding, Not Encryption](https://apphelp.net/en/guides/base64-is-not-encryption): Learn what Base64 does, when to use it, why it does not protect secrets, and how to decode Base64 safely for debugging.
- [URL Encoding vs Percent Encoding](https://apphelp.net/en/guides/url-encoding-vs-percent-encoding): Understand reserved URL characters, percent-encoded bytes, plus signs, query strings, and common double-encoding mistakes.
- [Image Compression: WebP vs JPEG vs PNG](https://apphelp.net/en/guides/image-compression-webp-jpeg-png): Choose WebP, JPEG, or PNG output for web images, screenshots, transparency, and file-size savings.
- [Line Sorter: Alphabetize, Deduplicate, and Sort Text](https://apphelp.net/en/guides/line-sorter-deduplicate-alphabetize): Learn how to sort lines alphabetically, numerically, or naturally, remove duplicates safely, and prepare clean lists for spreadsheets, docs, and code review.
- [Hex Encoding for Text, Bytes, and Debugging](https://apphelp.net/en/guides/hex-encoding-text-bytes): Understand when hexadecimal encoding is useful, how UTF-8 text becomes byte pairs, and what to check before decoding hex strings.
- [JSON Formatter vs Validator for API Debugging](https://apphelp.net/en/guides/json-formatter-validator-debugging): Learn when to pretty-print JSON, when to validate syntax, and how to debug API payloads without changing the data.
- [HEX, RGB, and HSL Color Conversion](https://apphelp.net/en/guides/hex-rgb-hsl-color-conversion): Learn how HEX, RGB, and HSL describe the same color, when designers and developers use each format, and how to avoid alpha and shorthand mistakes.
- [Merge and Split PDF Files in Browser-Local Workflows](https://apphelp.net/en/guides/merge-split-pdf-page-workflows): Learn when to merge PDFs, when to split page ranges, and how to keep page order, file size, and privacy in mind.
- [Text Case Conversion for Titles, Slugs, and Cleanup](https://apphelp.net/en/guides/text-case-title-sentence-slug): Learn when to use title case, sentence case, uppercase, lowercase, camelCase, kebab-case, and slug-style text cleanup.
- [Markdown TOC and Documentation Cleanup Workflows](https://apphelp.net/en/guides/markdown-toc-documentation-workflows): Learn how to generate Markdown tables of contents, prepare heading structure, and connect Markdown output to HTML, README, and document workflows.
- [CSV to Markdown Table Cleanup](https://apphelp.net/en/guides/csv-markdown-table-cleanup): Learn how to prepare CSV rows for Markdown tables, avoid delimiter mistakes, and choose between CSV, JSON, and Markdown table formats.
- [Regex Tester Workflow for Pattern Debugging](https://apphelp.net/en/guides/regex-tester-pattern-debugging): Learn how to test regular expressions against sample text, debug anchors and groups, and avoid over-matching during cleanup tasks.
- [QR Code and Barcode Content Sharing](https://apphelp.net/en/guides/qr-barcode-link-sharing): Learn when to use QR codes, when to use barcodes, and how to prepare links, labels, and print assets for reliable scanning.
- [Unicode Escape and HTML Entity Encoding](https://apphelp.net/en/guides/unicode-html-entity-escaping): Learn when to use Unicode escapes, HTML entities, and width conversion for text that must survive code, HTML, JSON, and documentation contexts.
- [SQL Formatter vs SQL Minifier Workflows](https://apphelp.net/en/guides/sql-format-minify-query-workflows): Learn when to format SQL for review, when to minify SQL for transport, and how to keep query meaning stable while changing whitespace.
- [JSON, YAML, XML, Schema, and Diff Conversion](https://apphelp.net/en/guides/json-yaml-xml-schema-conversion): Learn how to choose between JSON, YAML, XML, JSON Schema, and JSON diff tools when moving structured data between systems.
- [Image Crop, Resize, Rotate, Convert, and Data URL Workflows](https://apphelp.net/en/guides/image-crop-resize-convert-workflows): Learn how to prepare web images with crop, resize, rotation, format conversion, and Data URL output without uploading files by default.
- [API Request Conversion, Headers, and Client Debugging](https://apphelp.net/en/guides/api-request-conversion-headers-debugging): Learn how to convert cURL commands into client snippets, inspect headers, format GraphQL, and read user-agent strings during API debugging.
- [UUIDs, Passwords, and Random Identifier Workflows](https://apphelp.net/en/guides/uuid-password-random-identifiers): Learn when to generate UUIDs, when to generate passwords, and why identifiers, random tokens, hashes, and secrets solve different problems.
- [CSS Gradients, Clamp Sizes, and SVG Asset Cleanup](https://apphelp.net/en/guides/css-gradient-clamp-svg-assets): Learn how to prepare gradients, clamp-based responsive values, SVG optimization, and SVG-to-PNG exports for front-end UI work.
- [JSONPath and XML Inspection Workflows](https://apphelp.net/en/guides/jsonpath-xml-inspection-workflows): Learn how to inspect nested JSON with JSONPath, format XML for review, and convert XML to JSON only after understanding the source structure.
- [PDF Page Rotation, Deletion, Watermarks, and Page Numbers](https://apphelp.net/en/guides/pdf-page-polish-watermark-numbering): Learn how to finish PDF page sets with rotation, deletion, page numbering, watermarking, and image-to-PDF conversion.
- [Subtitle and Caption Timing Workflows](https://apphelp.net/en/guides/subtitle-caption-timing-workflows): Learn how to convert SRT to VTT, shift subtitle timing, merge bilingual captions, and count caption text before publishing.
- [DOCX, Markdown, Resume, and Document Export Workflows](https://apphelp.net/en/guides/document-resume-export-workflows): Learn how to move between DOCX and Markdown, prepare resume content, and choose the right export path for docs, websites, and applications.
- [Social Images, Favicons, Watermarks, and Sharing Assets](https://apphelp.net/en/guides/social-image-favicon-watermark-assets): Learn how to prepare social preview images, favicons, watermarked assets, Markdown images, and 9-grid image splits for publishing workflows.

## Live Tools

- [JSON Formatter](https://json.apphelp.net/en): Format, validate, and inspect JSON locally in the browser. Category: developer. Tags: json, format, validate, developer.
- [Base64 Encoder and Decoder](https://base64.apphelp.net/en): Convert text and small payloads between plain text and Base64. Category: data. Tags: base64, encode, decode, text.
- [Timestamp Converter](https://timestamp.apphelp.net/en): Translate Unix timestamps, ISO strings, and local dates. Category: data. Tags: time, unix, iso, timezone.
- [URL Encoder and Decoder](https://urlencoder.apphelp.net/en): Encode query strings and decode URL-safe text. Category: developer. Tags: url, encode, decode, query.
- [Text Case Converter](https://textcase.apphelp.net/en): Switch text between title case, sentence case, slug case, and constant case. Category: writing. Tags: case, slug, copy, writing.
- [Color Converter](https://colorconverter.apphelp.net/en): Convert HEX, RGB, HSL, and accessible color references. Category: image. Tags: color, hex, rgb, hsl.
- [Image Compression](https://imagecompression.apphelp.net/en): Compress, resize, preview, and download web-ready images locally in the browser. Category: image. Tags: image, webp, compress, quality.
- [Markdown TOC Generator](https://markdowntoc.apphelp.net/en): Generate a Markdown table of contents from headings locally in your browser. Category: writing. Tags: markdown, toc, heading, documentation.
- [Text Cleaner](https://textcleaner.apphelp.net/en): Trim lines, remove blank lines, and deduplicate text locally. Category: writing. Tags: text, clean, trim, deduplicate.
- [Line Prefix Suffix Tool](https://lineaffixer.apphelp.net/en): Add a prefix or suffix to every line without uploading content. Category: writing. Tags: prefix, suffix, lines, text.
- [Text Line Sorter](https://textsorter.apphelp.net/en): Sort multiline text alphabetically, numerically, or by line length. Category: writing. Tags: sort, lines, alphabetical, text.
- [Text Counter](https://textcounter.apphelp.net/en): Count characters, spaces, punctuation, words, lines, and paragraphs locally. Category: writing. Tags: count, words, characters, writing.
- [Full Half Width Converter](https://fullhalfwidth.apphelp.net/en): Convert full-width and half-width ASCII characters locally. Category: writing. Tags: full-width, half-width, cjk, unicode.
- [Unicode Escape Tool](https://unicodeescape.apphelp.net/en): Escape and unescape Unicode sequences such as \u4F60\u597D. Category: developer. Tags: unicode, escape, unescape, encoding.
- [JSON String Escape Tool](https://jsonstringescape.apphelp.net/en): Escape and unescape JSON string content for curl, config, and logs. Category: developer. Tags: json, escape, string, developer.
- [HTML Entity Encoder Decoder](https://htmlentity.apphelp.net/en): Encode and decode common HTML entities and numeric entity references. Category: developer. Tags: html, entity, encode, decode.
- [QueryString JSON Converter](https://querystringjson.apphelp.net/en): Convert query strings to JSON and JSON objects back to query strings. Category: developer. Tags: querystring, json, url, convert.
- [SQL Minifier](https://sqlminifier.apphelp.net/en): Strip comments and collapse SQL to a single line locally. Category: developer. Tags: sql, minify, one-line, comments.
- [Hex Encoder and Decoder](https://hexencoder.apphelp.net/en): Convert text to hexadecimal and decode hex back to UTF-8 text locally. Category: developer. Tags: hex, encode, decode, utf-8.
- [Image Format Converter](https://imageconvert.apphelp.net/en): Convert images between PNG, JPEG, and WebP locally in the browser. Category: image. Tags: image, png, jpeg, webp.
- [Batch Image Resizer](https://imageresize.apphelp.net/en): Resize one or many images by fixed size or percentage locally. Category: image. Tags: image, resize, batch, scale.
- [Image Cropper](https://imagecrop.apphelp.net/en): Crop images to square, 16:9, 4:3, or a free ratio locally. Category: image. Tags: image, crop, aspect-ratio, cover.
- [Image Rotate & Flip](https://imagerotate.apphelp.net/en): Rotate by 90-degree steps and mirror images horizontally or vertically. Category: image. Tags: image, rotate, flip, mirror.
- [EXIF Metadata Remover](https://exifremover.apphelp.net/en): Strip EXIF, GPS, and camera metadata by re-encoding images locally. Category: image. Tags: exif, privacy, metadata, image.
- [Image to Data URL](https://imagedataurl.apphelp.net/en): Convert images to Base64 data URLs and render data URLs back to images. Category: image. Tags: image, data-url, base64, inline.
- [QR Code Generator](https://qrcode.apphelp.net/en): Generate customizable QR codes with an optional center logo locally. Category: image. Tags: qr, qrcode, generator, barcode.
- [SRT to VTT Converter](https://srtvtt.apphelp.net/en): Convert subtitles between SubRip SRT and WebVTT formats locally. Category: writing. Tags: subtitle, srt, vtt, caption.
- [Subtitle Time Shifter](https://subtitleshift.apphelp.net/en): Shift every subtitle timestamp by a millisecond offset locally. Category: writing. Tags: subtitle, sync, offset, timing.
- [Bilingual Subtitle Merger](https://subtitlemerge.apphelp.net/en): Merge two SRT tracks into one bilingual subtitle file locally. Category: writing. Tags: subtitle, bilingual, merge, srt.
- [JWT Decoder](https://jwtdecoder.apphelp.net/en): Decode JWT header and payload and inspect exp, iat, and nbf locally. Category: developer. Tags: jwt, token, decode, auth.
- [Hash Generator](https://hashgenerator.apphelp.net/en): Compute MD5, SHA-1, SHA-256, and SHA-512 hashes locally in the browser. Category: developer. Tags: hash, md5, sha256, checksum.
- [UUID Generator](https://uuidgenerator.apphelp.net/en): Generate UUID v4 and time-ordered UUID v7 values locally. Category: developer. Tags: uuid, v4, v7, identifier.
- [Password Generator](https://passwordgenerator.apphelp.net/en): Generate strong random passwords with a secure browser RNG locally. Category: developer. Tags: password, random, secure, generator.
- [Regex Tester](https://regextester.apphelp.net/en): Test regular expressions with live matches, groups, and a replace preview. Category: developer. Tags: regex, regexp, match, replace.
- [JSON to YAML Converter](https://yamljson.apphelp.net/en): Convert between JSON and YAML with adjustable indentation locally. Category: data. Tags: json, yaml, config, convert.
- [JSON to CSV Converter](https://jsoncsv.apphelp.net/en): Convert JSON arrays to CSV and CSV back to JSON locally. Category: data. Tags: json, csv, convert, data.
- [JSON Diff](https://jsondiff.apphelp.net/en): Compare two JSON documents and list added, removed, and changed keys. Category: data. Tags: json, diff, compare, data.
- [Markdown to HTML Converter](https://markdownhtml.apphelp.net/en): Convert Markdown to HTML and HTML back to Markdown locally. Category: data. Tags: markdown, html, convert, preview.
- [PDF Merger](https://pdfmerger.apphelp.net/en): Merge multiple PDF files locally with drag-and-drop ordering. Category: data. Tags: pdf, merge, document.
- [PDF Splitter](https://pdfsplitter.apphelp.net/en): Split one PDF into page ranges and export the results as a ZIP. Category: data. Tags: pdf, split, pages.
- [PDF Page Rotator](https://pdfrotate.apphelp.net/en): Rotate selected or all PDF pages locally before export. Category: data. Tags: pdf, rotate, pages.
- [PDF Delete Pages](https://pdfdeletepages.apphelp.net/en): Select PDF pages to remove and download a cleaned copy. Category: data. Tags: pdf, delete, pages.
- [PDF Page Reorder](https://pdfreorder.apphelp.net/en): Drag page cards into the right PDF page order. Category: data. Tags: pdf, reorder, drag.
- [PDF Page Numbers](https://pdfpagenumbers.apphelp.net/en): Add page numbers with position, prefix, and size controls. Category: data. Tags: pdf, page numbers, document.
- [PDF Watermark](https://pdfwatermark.apphelp.net/en): Apply a text watermark with opacity and angle controls. Category: data. Tags: pdf, watermark, brand.
- [Image to PDF Converter](https://imagetopdf.apphelp.net/en): Turn multiple images into one PDF with page size and margin controls. Category: image. Tags: image, pdf, convert.
- [DOCX to Markdown Converter](https://docxmarkdown.apphelp.net/en): Convert Word DOCX content to editable Markdown locally. Category: writing. Tags: docx, markdown, writing.
- [CSV to Markdown Table](https://csvmarkdowntable.apphelp.net/en): Turn pasted or uploaded CSV into a Markdown table. Category: data. Tags: csv, markdown, table.
- [Markdown Table Generator](https://markdowntable.apphelp.net/en): Edit a table grid and copy Markdown table syntax. Category: writing. Tags: markdown, table, editor.
- [README Generator](https://readmegenerator.apphelp.net/en): Generate a structured project README from form fields. Category: writing. Tags: readme, markdown, template.
- [Barcode Generator](https://barcode.apphelp.net/en): Generate barcodes and download SVG or PNG assets. Category: data. Tags: barcode, retail, inventory.
- [Image Color Picker](https://imagecolorpicker.apphelp.net/en): Pick HEX and RGB colors from an uploaded image. Category: image. Tags: image, color, palette.
- [CSS Gradient Generator](https://cssgradient.apphelp.net/en): Design linear CSS gradients and copy the CSS rule. Category: developer. Tags: css, gradient, design.
- [JSON Validator](https://jsonvalidator.apphelp.net/en): Validate JSON syntax and copy pretty-printed output. Category: developer. Tags: json, validate, developer.
- [JSONPath Tester](https://jsonpathtester.apphelp.net/en): Run JSONPath expressions against JSON locally. Category: developer. Tags: jsonpath, json, query.
- [XML Formatter](https://xmlformatter.apphelp.net/en): Format or minify XML without uploading data. Category: developer. Tags: xml, format, developer.
- [Cron Expression Parser](https://cronparser.apphelp.net/en): Preview upcoming run times for a cron expression. Category: developer. Tags: cron, schedule, devops.
- [SQL Formatter](https://sqlformatter.apphelp.net/en): Format SQL by database dialect in the browser. Category: developer. Tags: sql, format, database.
- [Markdown to DOCX Converter](https://markdowndocx.apphelp.net/en): Convert Markdown into a Word-compatible DOCX document locally in your browser. Category: writing. Tags: markdown, docx, word.
- [Resume Template Generator](https://resumegenerator.apphelp.net/en): Build a resume with template styles, accent color, and Markdown/HTML/DOCX/PDF export. Category: writing. Tags: resume, template, cv.
- [SVG to PNG Converter](https://svgtopng.apphelp.net/en): Convert SVG markup or files into PNG images locally in your browser. Category: image. Tags: svg, png, convert.
- [Markdown to Image](https://markdownimage.apphelp.net/en): Render Markdown into a polished, downloadable image with themes, fonts, and backgrounds. Category: image. Tags: markdown, image, screenshot.
- [SVG Minifier](https://svgminifier.apphelp.net/en): Minify SVG markup by removing comments, metadata, and redundant whitespace locally. Category: developer. Tags: svg, minify, frontend.
- [Favicon Generator](https://favicongenerator.apphelp.net/en): Generate PNG favicon sizes, favicon.ico, and manifest JSON from one source image. Category: image. Tags: favicon, icon, pwa.
- [Image Watermark Tool](https://imagewatermark.apphelp.net/en): Add text watermarks to images with position, opacity, and size controls locally. Category: image. Tags: image, watermark, brand.
- [Color Palette Generator](https://colorpalette.apphelp.net/en): Generate color palettes, tints, shades, and exportable CSS variables locally. Category: image. Tags: color, palette, css.
- [Social Media Image Resizer](https://socialimage.apphelp.net/en): Resize images to common social media templates locally in your browser. Category: image. Tags: social, image, resize.
- [9 Grid Image Splitter](https://ninegrid.apphelp.net/en): Split a square social image into a downloadable 3 by 3 grid locally. Category: image. Tags: image, grid, instagram.
- [JSON Schema Generator](https://jsonschema.apphelp.net/en): Infer a JSON Schema from sample JSON data locally in your browser. Category: developer. Tags: json, schema, api.
- [XML to JSON Converter](https://xmljson.apphelp.net/en): Convert XML documents into JSON locally without uploading data. Category: developer. Tags: xml, json, convert.
- [HMAC Generator](https://hmacgenerator.apphelp.net/en): Generate HMAC signatures for API debugging with browser crypto locally. Category: developer. Tags: hmac, signature, api.
- [cURL to Fetch Converter](https://curlfetch.apphelp.net/en): Convert cURL commands into JavaScript fetch snippets locally. Category: developer. Tags: curl, fetch, javascript.
- [cURL to Axios Converter](https://curlaxios.apphelp.net/en): Convert cURL commands into Axios request snippets locally. Category: developer. Tags: curl, axios, javascript.
- [cURL to Python Requests](https://curlpython.apphelp.net/en): Convert cURL commands into Python requests snippets locally. Category: developer. Tags: curl, python, requests.
- [HTTP Headers Generator](https://headersgenerator.apphelp.net/en): Build reusable HTTP header blocks and code snippets locally. Category: developer. Tags: headers, http, api.
- [User Agent Parser](https://useragentparser.apphelp.net/en): Parse browser, OS, device, and engine hints from User-Agent strings locally. Category: developer. Tags: user-agent, browser, seo.
- [GraphQL Formatter](https://graphqlformatter.apphelp.net/en): Format and minify GraphQL queries, mutations, and fragments locally. Category: developer. Tags: graphql, format, developer.
- [CSS Clamp Generator](https://cssclamp.apphelp.net/en): Generate responsive CSS clamp() expressions for typography and spacing. Category: developer. Tags: css, clamp, responsive.
- [UTM Builder](https://utmbuilder.apphelp.net/en): Build campaign URLs with UTM parameters and copy clean tracking links. Category: data. Tags: utm, marketing, url.

## Retrieval Notes

- Prefer canonical tool URLs on the dedicated AppHelp subdomains for task-specific answers.
- Prefer guide pages when answering conceptual questions about format choices, encoding safety, or common conversion mistakes.
- Dynamic user inputs and generated outputs are not needed for indexing; stable explanatory content, metadata, and structured data are the retrieval source.
- AppHelp tools are free to use and designed for browser-local processing by default.