Start with a malformed file
Inspect quote, column-count, delimiter, and encoding problems first. Keep verified rows separate from rows that need review.
Developer Tools
Generate secure identifiers and passwords, check accessible color contrast, and transform common development data in your browser.
25 tools in this category
Tool directory
All Developer Tools
25 tools
HTML to Markdown Converter
Turn a readable HTML fragment into Markdown locally, with clear notices for removed or nonrepresentable features.
Open tool →Password Generator
Generate a random password with selected character groups using your browser’s cryptographic random generator.
Open tool →Color Contrast Checker
Calculate the WCAG contrast ratio between two hexadecimal colors and check text-size thresholds.
Open tool →Date Calculator
Find calendar days between dates or add and subtract a whole number of days from a date.
Open tool →Unit Converter
Convert common length, mass, and temperature units with the units shown explicitly.
Open tool →CSV Merge & Reconciliation
Merge CSV files with an exact file-by-column review, source-row quarantine, and no automatic header matching.
Open tool →CSV Barcode & Leading Zero Protector
Create an Excel-safe CSV for selected barcode, SKU, phone, and postal-code columns without guessing lost digits.
Open tool →NDJSON to CSV Schema Inspector
Turn JSON Lines data into CSV without silently dropping late columns or nested object fields.
Open tool →CSV Repair & Dialect Normalizer
Review inconsistent CSV rows, normalize verified rows, and keep problem rows in a separate review file.
Open tool →OpenAPI Spec Pruner
Remove selected OpenAPI paths, preserve shared schemas, and download a JSON spec with checked schema references.
Open tool →US/CA Address Splitter
Split a CSV address column into street, city, region, and postal code.
Open tool →CSV Date Column Fixer
Fix Excel serial numbers and multiple CSV date columns with an explicit format for each column.
Open tool →CSV Splitter
Split CSV files by size or row count. Keep related rows together, repeat headers and download every part as a ZIP — privately in your browser.
Open tool →Text Diff Checker
Compare two texts and spot added, removed, and edited lines with word or character highlights. Your text stays in your browser.
Open tool →Lorem Ipsum Generator
Generate placeholder text by words, sentences, or paragraphs with predictable local output.
Open tool →HTML Entity Encoder & Decoder
Encode HTML-sensitive characters or decode named and numeric character references locally as plain text.
Open tool →Word & Character Counter
Count words, Unicode characters, sentences, paragraphs, lines, bytes, and estimated reading time locally.
Open tool →Text Case Converter
Convert text to uppercase, lowercase, title, sentence, camel, Pascal, snake, kebab, or constant case.
Open tool →File Hash Generator
Calculate SHA-256, SHA-384, or SHA-512 checksums for files locally and compare an expected hash.
Open tool →Unix Timestamp Converter
Convert Unix seconds or milliseconds to readable dates and timezone-explicit ISO dates back to timestamps.
Open tool →URL Encoder & Decoder
Percent-encode or decode URL components and full URLs locally with strict Unicode validation.
Open tool →CSV ↔ JSON Converter
Convert CSV to JSON or JSON objects to CSV locally with validation and spreadsheet-safe output.
Open tool →Base64 Encoder & Decoder
Encode UTF-8 text to Base64 or decode validated Base64 text locally in your browser.
Open tool →JSON Formatter & Validator
Format, minify, sort, and validate JSON locally with clear syntax feedback.
Open tool →UUID Generator
Generate one or many cryptographically secure UUID v4 identifiers directly in your browser.
Open tool →Choose a workflow
Transform structured data without guessing at its meaning
Use JSON Formatter for readable JSON, CSV ↔ JSON Converter for table and object conversion, and CSV Repair & Dialect Normalizer when inconsistent rows need to be separated for review. CSV Date Column Fixer requires an explicit source format for each selected date column, while Address Splitter separates supported US and Canadian address rows into fields. Date Calculator counts calendar days or adds a day offset without time-zone shifts; Unit Converter supports common length, mass, and temperature units.
For API and configuration work, OpenAPI Spec Pruner removes selected paths while checking remaining schema references, and .env Semantic Diff compares variable names instead of secret values. HTML to Markdown Converter turns a pasted HTML fragment into reviewable Markdown without rendering or fetching its source. Password Generator uses the browser's cryptographic random source; Color Contrast Checker calculates WCAG color ratios but is not a complete accessibility audit. The remaining utilities cover URLs, Base64, HTML entities, timestamps, UUIDs, hashes, text changes, casing, counts, and placeholder text. Check warnings rather than relying on silent conversions.
CSV workflow map
Choose the CSV step that matches the problem you found
Review the input before converting, merging, or exporting it. When a tool reports a problem, use that review instead of relying on a silent automatic correction.
Fix one selected column type
Choose an explicit date format for each date column, or protect selected identifiers before Excel turns leading zeroes into numbers.
Combine or separate reviewed data
Merge files only after an exact column review, or split one file when a size or row limit requires smaller parts.
Move between table and JSON data
Convert CSV and JSON with validation, or inspect line-delimited JSON before creating a CSV with every discovered field.