API Documentation
Most Utilerio tools are also available as a simple REST API. Call them from your own code — no SDK required.
Authentication
Every endpoint requires an API key sent in the X-API-Key header, scoped to the tools you enable when you create the key.
X-API-Key: YOUR_KEYBase URL
https://utilerio.comRate limits
Requests are rate limited per client. If you exceed the limit you receive a 429 response; retry after a short wait.
Endpoints
Barcode & Label Tools
ZPL Viewer
POST /api/v1/zpl/renderPaste Zebra ZPL code and see the rendered label instantly.
QR Code Reader
POST /api/v1/qr-readerDecode QR codes from an uploaded image or a public image URL.
Bulk Label Generator
POST /api/v1/bulk-label-generatorTurn a label template and a spreadsheet into hundreds of ready-to-print ZPL labels.
GS1 Barcode Parser
POST /api/v1/tools/gs1-parserDecode GS1 Application Identifiers from raw or bracketed barcode data — GTIN, batch, dates, serial and more.
ZPL to PDFBrowser tool
Turn a ZPL label file into a print-ready PDF at 203, 300 or 600 DPI.
ZPL to PNGBrowser tool
Export a ZPL label as a PNG image you can drop into docs or tickets.
Barcode GeneratorBrowser tool
Create Code 128, Code 39, EAN, UPC-A, ITF and Codabar barcodes as PNG or SVG.
QR Code GeneratorBrowser tool
Build QR codes for text, links, email, phone numbers and Wi-Fi networks.
Visual Label DesignerBrowser tool
Design a shipping or product label with text, barcodes, a logo and boxes, and export it as ZPL.
Image to ZPLBrowser tool
Convert a logo image into ZPL graphic field data at any print size, DPI and threshold.
Barcode ReaderBrowser tool
Read Code 128, Code 39, EAN, UPC, Data Matrix, PDF417 and other barcodes from an uploaded image.
Shipping Label ResizerBrowser tool
Select a label area on a PDF page and export it scaled to fit a real label size like 100×150mm.
Developer Tools
Markdown to HTML
POST /api/v1/markdownConvert Markdown to HTML with a live preview. Expose it as an API.
SQL Formatter
POST /api/v1/sql-formatFormat and beautify SQL queries for MySQL, PostgreSQL, SQLite and more.
Text Diff Checker
POST /api/v1/diffCompare two texts side-by-side and highlight additions, deletions and changes.
JSON Formatter
POST /api/v1/tools/json-formatterPretty-print or minify JSON, with the exact position of any syntax error.
JSON Minifier
POST /api/v1/tools/json-minifierStrip whitespace from JSON to produce the smallest possible payload.
JSON Validator
POST /api/v1/tools/json-validatorCheck whether a document is valid JSON and get the line, column and reason when it is not.
Base64 Encoder / Decoder
POST /api/v1/tools/base64-encoder-decoderEncode and decode Base64 text or files, including data URLs.
URL Encoder / Decoder
POST /api/v1/tools/url-encoder-decoderPercent-encode or decode URLs and query string components.
HTML Encoder / Decoder
POST /api/v1/tools/html-encoder-decoderEncode special characters as HTML entities and decode them back.
UUID Generator
POST /api/v1/tools/uuid-generatorGenerate cryptographically random UUID v4 values in bulk.
Hash Generator
POST /api/v1/tools/hash-generatorGenerate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text.
Unix Timestamp Converter
POST /api/v1/tools/unix-timestamp-converterConvert between Unix time and human dates in any timezone.
Number Base Converter
POST /api/v1/tools/number-base-converterConvert numbers between decimal, hexadecimal, binary and octal instantly.
Excel / CSV to SQL INSERT
POST /api/v1/tools/spreadsheet-to-sqlTurn an Excel sheet or CSV into batched SQL INSERT statements for Postgres, MySQL or SQL Server.
Env File Diff
POST /api/v1/tools/env-diffCompare two .env files by key and see exactly what was added, removed or changed.
docker run to Compose
POST /api/v1/tools/docker-run-to-composePaste a docker run command and get the equivalent docker-compose.yml service.
.gitignore Generator
POST /api/v1/tools/gitignore-generatorPick your languages, frameworks and editors, merge their common .gitignore rules into one file.
Test Data Generator
POST /api/v1/tools/mock-data-generatorGenerate synthetic user, product or custom records as JSON, CSV or SQL, from a seed.
JSON to Model Class
POST /api/v1/tools/json-to-modelGenerate C#, Java or Python model classes from a JSON sample.
JSON to TypeScript
POST /api/v1/tools/json-to-typescriptTurn a JSON sample into ready-to-use TypeScript interfaces.
JSON Query Tester (JMESPath)
POST /api/v1/tools/json-query-testerTest a JMESPath query against a JSON document and see the extracted result instantly.
YAML ↔ JSON Converter
POST /api/v1/tools/yaml-json-converterConvert YAML to JSON or JSON to YAML instantly, right in your browser.
Semver Comparator
POST /api/v1/tools/semver-comparatorCompare two semantic versions or check whether a version satisfies a range.
Nano ID / ULID Generator
POST /api/v1/tools/nanoid-ulid-generatorGenerate URL-safe Nano IDs or sortable, timestamp-based ULIDs in bulk.
JWT Encoder
POST /api/v1/tools/jwt-encoderBuild and sign a JSON Web Token with HS256, HS384 or HS512 using your own secret.
CIDR / Subnet Calculator
POST /api/v1/tools/cidr-calculatorGet network address, broadcast, netmask and usable host range from any CIDR block.
Test Credit Card Generator
POST /api/v1/tools/credit-card-generatorGenerate Luhn-valid test card numbers with expiry and CVV for development and QA.
cURL to Code
POST /api/v1/tools/curl-to-codeTurn a cURL command into JavaScript Fetch, C# HttpClient or Python Requests code.
Color Contrast Checker
POST /api/v1/tools/color-contrast-checkerCheck whether a text and background color pair meets WCAG AA or AAA contrast.
JWT DecoderBrowser tool
Decode and inspect JWT header, payload and signature without a secret.
Regex TesterBrowser tool
Write and test regular expressions against sample text with live highlights.
Password GeneratorBrowser tool
Generate strong, cryptographically random passwords with custom rules.
Color ConverterBrowser tool
Convert colors between HEX, RGB and HSL instantly with a live preview.
XML FormatterBrowser tool
Format, indent and validate XML documents in your browser.
URL ParserBrowser tool
Parse any URL into its components: protocol, host, path, query params and hash.
Cron Expression ParserBrowser tool
Translate CRON expressions into human-readable schedules with next run times.
Chmod CalculatorBrowser tool
Calculate Unix file permissions visually and get the chmod octal and symbolic notation.
JSON DiffBrowser tool
Compare two JSON objects and highlight added, removed and changed keys.
CSS MinifierBrowser tool
Remove whitespace and comments from CSS to reduce file size.
Base32 Encoder / DecoderBrowser tool
Encode text to RFC 4648 Base32 or decode it back, the format behind TOTP secrets.
JavaScript MinifierBrowser tool
Minify JavaScript to reduce file size, using the same engine as production build tools.
JSON Schema Generator & ValidatorBrowser tool
Infer a JSON Schema from a sample document, or validate JSON against a schema you already have.
OpenAPI Viewer & ValidatorBrowser tool
Paste an OpenAPI or Swagger spec to browse its endpoints and catch structural mistakes.
HMAC Generator & ValidatorBrowser tool
Compute an HMAC signature for a message and secret, or verify one you received matches.
Certificate / CSR DecoderBrowser tool
Decode a PEM-encoded X.509 certificate or CSR and see its subject, issuer, validity and SANs.
Code to ImageBrowser tool
Turn a code snippet into a syntax-highlighted, shareable PNG — no IDE screenshot needed.
File Conversion Tools
CSV to JSON
POST /api/v1/tools/csv-to-jsonConvert a CSV file or pasted rows into a JSON array.
JSON to CSV
POST /api/v1/tools/json-to-csvFlatten a JSON array into a CSV that opens cleanly in Excel.
XML to JSON
POST /api/v1/tools/xml-to-jsonConvert XML documents to readable JSON without touching a server.
JSON to XML
POST /api/v1/tools/json-to-xmlTurn JSON into well-formed XML with a root element you choose.
CSV Editor & Validator
POST /api/v1/tools/csv-editor-validatorEdit CSV data in a spreadsheet-like grid and check it for missing required fields or duplicate keys.
Spreadsheet Data Masking
POST /api/v1/tools/data-maskingMask sensitive columns in an Excel or CSV file before sharing it — full, partial, hashed or email masking.
Table Merge
POST /api/v1/tools/table-mergeStack two spreadsheets into one, or join them on a shared key column like a SQL join.
Excel / CSV Comparator
POST /api/v1/tools/spreadsheet-diffCompare two spreadsheets by a key column and see added, removed and changed rows.
Pivot Table Generator
POST /api/v1/tools/pivot-table-generatorSummarize an Excel or CSV file into a pivot table — pick row, column and value fields and an aggregation.
Excel ↔ CSV / JSON ConverterBrowser tool
Export an Excel sheet as CSV or JSON, or build a new .xlsx file from CSV or JSON data.
JSON Flatten / UnflattenBrowser tool
Flatten nested JSON to dot/bracket-path keys, or rebuild the nested structure from flat keys.
PDF Tools
PDF Page Organizer
POST /api/v1/pdf/organizeReorder, delete or duplicate pages by dragging thumbnails, then download the reorganized PDF.
PDF Page Numbers
POST /api/v1/pdf/page-numbersAdd page numbers to a PDF — choose the position, font size, starting number, format and page range.
PDF Form Filler
POST /api/v1/pdf/form-fillFill a PDF's text, checkbox, radio and dropdown fields, then download it editable or flattened.
PDF Signature Stamp
POST /api/v1/pdf/stamp-imageDraw or upload a signature, place it on any page at any size, and download the signed PDF.
Watermark PDF
POST /api/v1/pdf/watermarkStamp a text watermark across every page of a PDF, tiled or centered, with adjustable opacity and rotation.
Markdown to PDF
POST /api/v1/markdown-to-pdfConvert Markdown to a real, text-selectable PDF — headings, lists, tables, code blocks and links.
Merge PDFBrowser tool
Combine several PDF files into one, in the order you choose.
Split PDFBrowser tool
Split a PDF into single pages or extract page ranges as separate files.
Compress PDFBrowser tool
Reduce PDF file size in your browser with a quality level you choose.
Rotate PDFBrowser tool
Rotate all pages or specific pages of a PDF by 90, 180 or 270 degrees.
JPG to PDFBrowser tool
Turn JPG and PNG images into a single PDF, one image per page.
PDF to JPGBrowser tool
Convert each page of a PDF into a high-quality JPG image.
PDF to TextBrowser tool
Extract the selectable text layer from a PDF, page by page, and download it as .txt.
PDF Table to ExcelBrowser tool
Draw a box around a table in a PDF, mark its columns, and export exactly that data as Excel or CSV.
PDF CompareBrowser tool
Compare two PDFs page by page — see the exact text changes, or a highlighted visual diff.
Image Tools
Image Metadata (EXIF) Viewer
POST /api/v1/image/metadataView a photo's camera, date and GPS EXIF data, or download a copy with it stripped.
Base64 to Image
POST /api/v1/base64-to-imagePaste a Base64 string or data URL and decode it back into a downloadable image.
CSS Gradient & Shadow Generator
POST /api/v1/tools/css-gradient-shadow-generatorBuild a linear or radial gradient, or a multi-layer box-shadow, with a live preview and copyable CSS.
SVG Optimizer
POST /api/v1/tools/svg-optimizerShrink an SVG's file size by stripping redundant markup — see the before/after size and a live preview.
SVG Sprite Generator
POST /api/v1/tools/svg-sprite-generatorCombine multiple SVG icons into one symbol-based sprite sheet, with a ready-to-use usage example.
Compress ImageBrowser tool
Reduce JPG, PNG or WebP file size with a quality level you choose.
Resize ImageBrowser tool
Change an image's width and height, with an optional locked aspect ratio.
Convert ImageBrowser tool
Convert images between JPG, PNG and WebP in your browser.
Crop ImageBrowser tool
Drag a selection over your image and crop it to the exact region you need.
Image to Base64Browser tool
Turn an image into a Base64 data URL, with ready CSS and HTML snippets.
Watermark ImageBrowser tool
Stamp a text watermark across a JPG, PNG or WebP image, tiled or in one corner.
Favicon GeneratorBrowser tool
Turn one image into every favicon size a site needs, with the ready-to-paste HTML.
Image to Text (OCR)Browser tool
Extract editable text from a photo or screenshot in English or Turkish, entirely in your browser.
Image Color Palette ExtractorBrowser tool
Pull the dominant colors out of an image as hex, RGB, HSL and ready-to-use CSS variables.
Image Comparison ToolBrowser tool
Compare two images side by side, with a reveal slider, or as a pixel-level difference overlay.
Image JoinerBrowser tool
Combine several images into one — stacked horizontally, vertically, or arranged in a grid.
E-Commerce Tools
SKU Generator
POST /api/v1/tools/sku-generatorGenerate SKUs from brand, category, color and size, in bulk across every color×size combination.
Product Feed Validator
POST /api/v1/tools/product-feed-validatorCheck a Google Shopping-style XML product feed for missing fields, duplicate IDs and bad price/URL formats.
Bulk Price Updater
POST /api/v1/tools/bulk-price-updaterApply a percentage or fixed adjustment to a spreadsheet's price column, with min/max and rounding rules.
Marketplace Profit Calculator
POST /api/v1/tools/marketplace-profit-calculatorSee what is left after commission, shipping, packaging and VAT.
Volumetric Weight CalculatorBrowser tool
Work out dimensional shipping weight from width, length and height.
Quote / Proforma Invoice GeneratorBrowser tool
Build a quote or proforma invoice with your logo, line items, discounts and tax, and download it as a PDF.
Business Calculators
ROAS & Break-Even Calculator
POST /api/v1/tools/roas-break-even-calculatorCalculate ROAS and the break-even ROAS from ad spend, revenue and contribution margin.
VAT CalculatorBrowser tool
Add VAT to a net price or strip it out of a gross price.
Discount CalculatorBrowser tool
Apply one or more discounts and see the real effective rate.
Profit Margin CalculatorBrowser tool
Get profit, margin and markup from cost and selling price.
Percentage CalculatorBrowser tool
Calculate percentages, percentage change and what percent X is of Y.
Age & Date Difference CalculatorBrowser tool
Calculate exact age or the difference between two dates in years, months and days.
Temperature ConverterBrowser tool
Convert temperatures between Celsius, Fahrenheit and Kelvin instantly.
Stock Coverage CalculatorBrowser tool
Calculate how many days your current stock will last and the reorder point that keeps you from running out.
Text Tools
Slug Generator
POST /api/v1/tools/slug-generatorTurn any title into a clean, URL-friendly slug in one click.
Case Converter
POST /api/v1/tools/case-converterConvert text to camelCase, PascalCase, snake_case, kebab-case and more.
List Compare
POST /api/v1/tools/list-compareCompare two lists line by line — find what's only in each, their intersection, union and duplicates.
Find and Replace
POST /api/v1/tools/find-replaceFind and replace text with plain matching or a regular expression, with a live match count.
Text Cleaner
POST /api/v1/tools/text-cleanerTrim whitespace, collapse repeated spaces, remove blank lines and normalize line endings.
Word & Character CounterBrowser tool
Count words, characters, sentences and paragraphs in any text.
Text ReverserBrowser tool
Reverse characters, words or lines in any block of text.
Lorem Ipsum GeneratorBrowser tool
Generate placeholder text by paragraphs, sentences or words.
SEO Tools
DNS Lookup
GET /api/v1/net/dns-lookupLook up a domain's A, AAAA, MX, TXT, CNAME and NS records, with TTL and resolver info.
SSL Certificate Checker
GET /api/v1/net/ssl-checkCheck a website's TLS certificate: issuer, expiry date, days remaining and whether browsers trust it.
HTTP Header Checker
GET /api/v1/net/http-header-checkSee any public URL's status code and response headers, with short explanations for the cache and security ones.
Redirect Chain Checker
GET /api/v1/net/redirect-checkFollow a URL's redirects hop by hop and see the status code and destination at every step.
Broken Link Checker
GET /api/v1/net/broken-link-checkCrawl a site from a starting URL and find every link that returns an error or fails to load.
Robots.txt Generator
POST /api/v1/tools/robots-txt-generatorBuild a robots.txt with per-agent allow/disallow rules and a sitemap reference.
XML Sitemap Generator
POST /api/v1/tools/sitemap-generatorPaste a list of URLs to generate a standard XML sitemap, with optional lastmod, changefreq and priority.
Meta Tag Generator
POST /api/v1/tools/meta-tag-generatorGenerate title, description, Open Graph and Twitter Card meta tags, ready to paste into <head>.
Hreflang Tag Generator
POST /api/v1/tools/hreflang-generatorGenerate reciprocal hreflang link tags for a page's translations, with an optional x-default.
Schema Markup Generator
POST /api/v1/tools/schema-markup-generatorGenerate JSON-LD structured data for an Article, Product, FAQ page or Local Business.
UTM Link Builder
POST /api/v1/tools/utm-builderBuild one or many UTM-tagged campaign URLs from source, medium, campaign, term and content, export as CSV.
Keyword Density Analyzer
POST /api/v1/tools/keyword-density-analyzerSee the top single words and phrases in a text, with a density check for a focus keyword.
Readability Score Checker
POST /api/v1/tools/readability-score-checkerGet a Flesch Reading Ease score and grade level for English text, or an Ateşman score for Turkish.
Open Graph Image DesignerBrowser tool
Design a 1200×630 social share image with a title, subtitle, logo and gradient background.
Audio Tools
Audio TrimmerBrowser tool
Cut an audio file down to the exact start and end time you need, and download it as WAV.
Audio ConverterBrowser tool
Convert MP3, OGG, M4A and other audio formats your browser can play to WAV.
Video to AudioBrowser tool
Pull the audio track out of a video file and download it as WAV — nothing ever leaves your device.
Subtitle Converter & SyncBrowser tool
Convert subtitles between SRT and VTT, and shift every timestamp by a fixed offset to fix sync.
Audio JoinerBrowser tool
Combine several audio files into one, in the order you choose, and download it as WAV.