Developer utilities that run entirely in your browser
DevFixPro formats JSON, converts encodings, tests regex, and generates hashes right in your browser — 46 free tools, no upload, no account. Formatters, converters, encoders, and generators for everyday dev work — no upload, no accounts, no tracking. Open a tool and get the answer.
Browse developer errors by cause & fix
Not just a tool — a growing library of high-intent errors with a root-cause diagnosis and a step-by-step fix you can actually run. Filter by language or framework and jump straight to the fix.
Common developer errors, explained
High-intent errors with a root-cause diagnosis and a step-by-step fix — the part an AI answer box can describe but not run for you. Start from the errors developers search for most:
tf.config.experimental.set_memory_growth undefined / no effect
CUDA OOM even on small batches; set_memory_growth call throws or is ignored.
Cause, environments & fix →Linux / macOS shellsbash: ulimit -n: open files limit too low
EMFILE, 'too many open files', or watch/build processes crash under load.
Cause, environments & fix →Babylon.jsError: Babylon.js render context is not available
Engine fails to start; 'render context is not available' on mount.
Cause, environments & fix →JenkinsJenkins pipeline is unexpectedly slow
Stages take minutes longer than expected; idle gaps between steps.
Cause, environments & fix →Eclipse IDEEclipse launch error: cannot connect to VM / timeout
Application launch fails with 'Could not connect to the virtual machine' or a timeout.
Cause, environments & fix →KotlinTroubleshoot Kotlin compilation / unresolved reference
Unresolved reference, or compilation succeeds in IDE but fails in Gradle.
Cause, environments & fix →Choose a diagnostic path
Start from the symptom, generate a focused result, and print the steps you want to keep. All processing stays in your browser.
Validate structured data
Paste JSON and get a readable diagnosis with a corrected, copy-ready result.
Format and diagnose →Test a matching issue
Enter a pattern and sample text to see matches and refine the fix.
Run regex diagnosis →Interpret an HTTP failure
Look up a status and turn the symptom into a concise next-step checklist.
Find next steps →All tools
Every tool below processes your input on-device. Your code, tokens, and text never leave your browser.
JSON Formatter & Validator
Pretty-print, minify, or compact JSON and catch syntax errors instantly.
Open tool →JSON to CSV Converter
Flatten an array of JSON objects into downloadable CSV rows.
Open tool →CSV to JSON Converter
Turn pasted CSV text into an array of JSON objects.
Open tool →Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text, safely in your browser.
Open tool →JWT Decoder
Decode a JSON Web Token header and payload (base64url) to inspect claims.
Open tool →Regex Tester
Test a JavaScript regular expression against input and highlight every match.
Open tool →Cron Expression Parser
Translate a cron schedule into plain English and preview the next run times.
Open tool →Timestamp Converter
Convert Unix seconds or milliseconds to human-readable dates across time zones.
Open tool →URL Encoder / Decoder
Percent-encode or decode URLs and query-string components.
Open tool →Hash Generator
Compute MD5, SHA-1, SHA-256, or SHA-512 locally with the Web Crypto API.
Open tool →SQL Formatter
Pretty-print a SQL statement with keyword-aware indentation.
Open tool →UUID Generator
Generate one or many RFC-4122 v4 UUIDs with crypto.randomUUID().
Open tool →HTML Entity Encoder / Decoder
Escape or unescape HTML entities for safe markup and debugging.
Open tool →Case Converter
Convert identifiers between camelCase, snake_case, kebab-case, and PascalCase.
Open tool →Text Diff Viewer
Compare two blocks of text and see added and removed lines side by side.
Open tool →Number Base Converter
Convert integers between hexadecimal, binary, decimal, and octal.
Open tool →AES Encrypt / Decrypt
Encrypt or decrypt text with AES-256-GCM using a passphrase — all in your browser.
Open tool →HMAC Generator
Create HMAC-SHA256/384/512 message authentication codes from a secret key.
Open tool →ROT / Caesar Cipher
Shift letters with a Caesar cipher or apply ROT13 to obfuscate text.
Open tool →Base32 / Base58
Encode or decode data with Base32 (RFC 4648) or Bitcoin Base58.
Open tool →Morse Code
Translate text to and from International Morse code.
Open tool →Escape / Unescape
Escape or unescape strings for JavaScript, JSON, HTML, SQL, or CSV.
Open tool →Text Statistics
Count characters, words, lines, sentences, and UTF-8 bytes of any text.
Open tool →Line Tools
Sort, deduplicate, trim, drop blanks, reverse, or shuffle lines of text.
Open tool →Slug Generator
Turn a title or sentence into a clean, URL-safe slug.
Open tool →Roman Numeral Converter
Convert between Roman numerals and modern Arabic numbers (1–3999).
Open tool →String Similarity
Measure the Levenshtein distance and similarity ratio of two strings.
Open tool →XML Formatter
Pretty-print and validate XML with readable indentation.
Open tool →JSON Path Extractor
Extract nested values from JSON using simple dot-path notation.
Open tool →Color Converter
Convert colors between HEX, RGB, and HSL instantly.
Open tool →URL Parser
Break any URL into protocol, host, path, query, and fragment.
Open tool →CIDR / Subnet Calculator
Compute network range, broadcast, and usable hosts from an IPv4 CIDR.
Open tool →MIME Type Lookup
Find the MIME type for a file extension or look up an extension by MIME.
Open tool →Query String Parser
Parse, sort, and rebuild URL query strings into key/value pairs.
Open tool →Password Generator
Create strong, random passwords with customizable character rules.
Open tool →Lorem Ipsum Generator
Generate placeholder paragraphs, sentences, or words for mockups.
Open tool →Timezone Converter
Convert a date and time across world time zones with Unix epoch.
Open tool →Cross-Origin API Request Builder
Build and send real GET/POST/PUT/DELETE requests from your browser to debug APIs and CORS.
Open tool →CORS Error Diagnostic
Paste a CORS console error and get the likely cause and the server-side fix.
Open tool →HTTP Status Code Lookup
Look up what an HTTP status code means and the usual fix — 2xx, 3xx, 4xx, 5xx.
Open tool →Request Timeout & Latency Diagnostic
Compare a measured response time against your latency budget and find where to look.
Open tool →JavaScript Beautifier
Indent and tidy minified or hand-edited JavaScript in your browser, no upload.
Open tool →HTML / CSS Beautifier
Re-indent messy HTML or CSS markup for quick readability, locally.
Open tool →YAML / INI Config Linter
Catch tabs, trailing spaces, and malformed key/value lines in config files.
Open tool →Browser Cache Header Analyzer
Paste response headers and see whether a resource is fresh, revalidated, or never cached.
Open tool →CORS Header Generator
Generate Nginx / Apache CORS config and a matching fetch() example from your settings.
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