CodeAva
Developer Tools

Utilities that just work

Free online developer tools for secure passwords, cron schedules, JSON, JWT, Base64, regex, diffing, formatting, hashing, QR code generation, and HTTP header analysis.

Most Popular Tools

JSON Formatter & Validator

Beautify, minify, and validate JSON with syntax highlighting and clear error detection.

payload validationOpen

Secure Password & Passphrase Generator

Generate strong random passwords or memorable passphrases locally in your browser, with secure randomness, copy controls, and practical strength guidance.

local secret generationOpen

Diff Viewer

Compare two blocks of text or code line-by-line with additions and deletions highlighted.

content comparisonOpen

Regex Tester

Test regular expressions against sample text with real-time match highlighting.

pattern testingOpen

JWT Decoder

Decode JSON Web Tokens — inspect header, payload, and signature without a secret.

token inspectionOpen

Cron Parser, Builder & Timezone Translator

Parse cron expressions, build schedules visually, preview the next run times, and compare server UTC with your local timezone.

schedule debuggingOpen

HTTP Headers Checker

Fetch and inspect the HTTP response headers of any public URL in a clean, readable view.

response header analysisOpen

Image Optimizer

Compress, resize, and convert images to WebP and AVIF locally in your browser, with bulk processing, visual before/after comparison, and zero-server privacy.

image compressionOpen
Data & Encoding
11 tools

JSON Formatter & Validator

Beautify, minify, and validate JSON with syntax highlighting and clear error detection.

payload validationOpen

JSON Schema Validator & Generator

Validate JSON instances with pointer-based errors or generate a starter schema from sample data, entirely in your browser.

schema validation and generationOpen

JSON ↔ YAML Converter

Convert JSON to YAML and YAML to JSON instantly, validate structure, and clean up config files for APIs, CI/CD, and Kubernetes workflows.

config conversionOpen

OpenAPI & Swagger Validator Viewer

Validate OpenAPI 3.x JSON or YAML, check local references, and browse a compact endpoint and component summary.

API contract debuggingOpen

CSV ↔ JSON Converter & Cleaner

Convert CSV to JSON and JSON to CSV, auto-detect delimiters, clean messy exports, and flatten nested data safely in your browser.

data cleanupOpen

SQL Insert & Upsert Builder

Paste CSV, TSV, or Excel rows and generate safely-escaped bulk SQL — INSERT, PostgreSQL ON CONFLICT, MySQL ON DUPLICATE KEY UPDATE, SQLite upsert, and SQL Server MERGE.

SQL seed + backfill scriptsOpen

Base64 Encode / Decode

Instantly encode plain text to Base64 or decode Base64 strings back to readable text.

encoding & debuggingOpen

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates, auto-detect seconds vs milliseconds, and validate JWT expiry times faster.

timestamp debuggingOpen

UUID / ULID / Nano ID Generator

Generate UUID v4, UUID v7, ULIDs, and Nano IDs instantly, with bulk generation, copy tools, and sortable ID comparisons.

unique ID generationOpen

UUID / ULID Validator & Inspector

Validate UUIDs and ULIDs, auto-detect versions, extract embedded timestamps, and bulk-check identifiers safely in your browser.

ID debuggingOpen

JQ, JSONPath & XPath Workbench

Test jq, JSONPath, and XPath queries live against JSON, XML, or HTML payloads with smart path hints, readable errors, and shareable sessions.

API payloads, XML parsing, extraction debuggingOpen
Security & Validation
13 tools

Hash Generator

Generate SHA-1, SHA-256, and SHA-512 hashes from any text input using Web Crypto.

integrity checksOpen

Secure Password & Passphrase Generator

Generate strong random passwords or memorable passphrases locally in your browser, with secure randomness, copy controls, and practical strength guidance.

local secret generationOpen

Secure QR Code Decoder & Inspector

Decode QR codes from images, screenshots, or webcam input. Inspect URLs, Wi-Fi passwords, and contact cards safely before opening them — all locally in your browser.

QR inspectionOpen

JWT Generator & Mock Token Builder

Generate local test JWTs, customize claims, simulate expiry, and create intentionally invalid signatures for auth middleware testing — all locally in your browser.

auth testingOpen

CSP Evaluator & Violation Report Parser

Analyze Content Security Policy headers, flag unsafe-inline and unsafe-eval, parse browser violation reports into plain English, and generate deployment-ready CSP snippets locally in your browser.

CSP security auditingOpen

JWK/JWKS Inspector & JWT Signature Debugger

Inspect JWKS keys, match JWTs by kid, verify RS256, ES256, and HS256 signatures locally with Web Crypto, convert PEM ↔ JWK, and diagnose why token validation fails across Auth0, Okta, Cognito, and Firebase.

JWT signature debuggingOpen

X.509 / CSR / PEM Inspector

Decode certificates, CSRs, PEM bundles, and private keys locally. Inspect SANs, EKUs, validity, chain order, and key/cert matches without OpenSSL.

TLS debugging, CSR review, key/cert matchingOpen

SSL/TLS Certificate Chain Checker

Fetch a public host certificate, inspect SANs, validity and issuer chain, and surface hostname or trust errors.

live TLS chain diagnosisOpen

DMARC / SPF / DKIM Analyzer & Report Parser

Inspect email-authentication DNS records, spot SPF lookup-limit risks, review DMARC policy maturity, and parse DMARC aggregate XML reports into plain-English alignment insights — locally in your browser.

email deliverabilityOpen

Secure Email Header Analyzer & Hop Tracer

Paste raw email headers to trace delivery hops, inspect SPF/DKIM/DMARC/ARC results, flag spoofing clues, and explain spam-filter signals — locally in your browser.

phishing triage, deliverability debugging, mail hop tracingOpen

Punycode Converter & Homograph Inspector

Convert Unicode domains to ASCII Punycode, decode xn-- hostnames, and inspect suspicious domains for confusable characters, mixed scripts, and homograph phishing risk.

IDN decoding, phishing triage, suspicious domain reviewOpen

Webhook Signature Verifier & HMAC Playground

Verify HMAC webhook signatures locally, inspect the exact canonical string being hashed, and diagnose why Stripe, GitHub, Slack, or Shopify signature checks fail — with copy-ready verification code.

webhook debuggingOpen

SRI Hash Generator & Integrity Policy Helper

Generate Subresource Integrity hashes for JS and CSS assets, build exact integrity tags, and create Integrity-Policy headers with reporting support.

third-party scripts, CDN assetsOpen
Web Diagnostics
21 tools

JWT Decoder

Decode JSON Web Tokens — inspect header, payload, and signature without a secret.

token inspectionOpen

URL Parser, Encoder & UTM Query Builder

Parse URLs into clean components, decode query strings, edit parameters live, and build UTM-tagged campaign links safely in your browser.

URL debuggingOpen

Cron Parser, Builder & Timezone Translator

Parse cron expressions, build schedules visually, preview the next run times, and compare server UTC with your local timezone.

schedule debuggingOpen

AWS EventBridge Cron & Rate Expression Builder

Build valid AWS EventBridge Scheduler expressions, avoid day-field conflicts, preview the next runs, and compare UTC with your local timezone.

AWS schedulingOpen

Secure HAR Viewer, Analyzer & Secret Sanitizer

Inspect HAR files locally, rank slow requests, compare traces, and redact cookies, tokens, API keys, and other secrets before sharing.

HAR debugging, token redaction, network performance auditsOpen

HTTP Headers Checker

Fetch and inspect the HTTP response headers of any public URL in a clean, readable view.

response header analysisOpen

DNS Record Lookup & Propagation Checker

Inspect A, AAAA, CNAME, MX, TXT, NS, and CAA answers with conflict guidance and resolver comparison.

DNS and propagation debuggingOpen

Meta Tag & SERP Previewer

Draft SEO titles, meta descriptions, Open Graph tags, and social cards locally, with practical SERP and sharing previews before you publish.

SEO metadata draftingOpen

Schema.org JSON-LD Generator & Validator

Build, validate, and export structured data for Article, Product, Local Business, Event, Job Posting, and more — locally in your browser.

structured dataOpen

Slug Generator & URL Sanitizer

Convert messy titles into clean, SEO-friendly URL slugs, normalize accents, remove symbols, and generate bulk slugs locally in your browser.

URL slug creationOpen

Canonical URL Builder & Checker

Normalize messy URLs, strip tracking parameters, and generate clean rel="canonical" tags locally in your browser.

canonical tag generationOpen

URL Indexability Inspector

Inspect live status codes, redirect chains, robots directives, canonical tags, and hreflang signals to understand whether a URL is likely indexable.

indexability diagnosisOpen

Hreflang Cluster Validator

Validate reciprocal hreflang clusters, check ISO language-region codes, verify x-default fallback, and detect canonical-hreflang conflicts across multilingual and multi-regional pages.

international SEOOpen

Structured Data Validator & Rich Result Gap Checker

Validate JSON-LD, extract structured data from live pages, and find missing fields that may block Google rich result eligibility.

schema gap analysisOpen

Open Graph & Social Preview Inspector

Fetch any live URL, inspect Open Graph and Twitter/X tags, simulate social previews for Facebook, LinkedIn, Slack, and iMessage, and validate og:image dimensions before you share.

social preview debuggingOpen

Robots.txt Checker

Validate robots.txt syntax, test crawl rules by bot, and catch blocking mistakes that can hurt indexing.

crawl rule validationOpen

AI Crawler Rules Builder & robots.txt Generator

Generate SEO-safe robots.txt rules for AI crawlers, search bots, and archive bots. Block training bots without accidentally blocking search visibility.

AI bot control, robots.txt policyOpen

Sitemap Checker

Validate XML sitemaps, inspect listed URLs, and uncover technical issues that reduce crawl and index efficiency.

sitemap validationOpen

llms.txt Generator & Checker

Create and audit an experimental llms.txt file that gives AI tools a cleaner Markdown map of your site, docs, and core context.

AI-ready docs, Markdown context mapsOpen

Visual Subnet Calculator & CIDR Range Validator

Plan IPv4 and IPv6 networks visually, split subnets, check overlaps, and compare usable IPs across AWS, Azure, and Google Cloud.

CIDR planning, VPC subnetting, overlap checksOpen

Docker Compose Validator & Service Graph

Validate Compose files for port collisions, risky dependency patterns, missing env vars, and outdated syntax. Instantly generate a visual service graph.

Compose debugging, architecture diagrams, local stack validationOpen

What these tools cover

CodeAva tools are browser-based utilities built for the kinds of tasks that come up constantly during development: formatting a JSON response, decoding a JWT to inspect claims, comparing two text blocks, testing a regex pattern, or checking what headers a server is actually returning. Each tool is focused on one job and designed to give you a usable output immediately.

They are useful for developers reaching for a quick formatter or validator mid-session, QA engineers comparing payloads and testing input patterns, founders and technical site owners checking what their server is returning, and agencies reviewing client sites before or after launch.

Most tools process input locally in your browser using native browser APIs — nothing is sent to a server. A small number of tools, like the HTTP Headers Checker, make a server-side fetch to inspect the URL you provide. Each tool page notes what it does and does not transmit. No account or signup is required.

What you can do with CodeAva tools

Validate JSON before sending API payloadscatch syntax errors and structural issues before a request fails.
Convert JSON and YAML configs safelyswitch between API payloads and human-edited config formats without hand-fixing braces or indentation.
Clean spreadsheet and SaaS exports locallyconvert CSV customer lists or operational exports into JSON, or flatten JSON into CSV for spreadsheet workflows.
Decode JWT claims for faster auth debugginginspect token contents without needing the signing secret.
Compare text or code changes before publishingsee exactly what changed between two versions, line by line.
Format code snippets for reviews and documentationconsistent indentation for cleaner PRs, docs, and tutorials.
Inspect HTTP response headers after deploymentverify security headers, caching rules, and redirects are correct.
Generate hashes for integrity checksproduce SHA-256 or SHA-512 fingerprints to compare or verify values.
Parse cron schedules and preview next run timestranslate cron to plain language, validate the right dialect, and compare server timezone with local time.
Generate strong passwords or passphrases locallycreate random credentials in the browser with secure randomness and practical strength guidance.
Encode and decode Base64 strings quicklyuseful for working with credentials, tokens, and binary data in transit.
Create QR codes for URLs and campaign assetsgenerate scannable codes for print, signage, or link sharing.
Convert Unix timestamps while debugging logs or APIsauto-detect seconds vs milliseconds and switch between UTC and local time.
Generate unique IDs for databases, APIs, and distributed systemscreate UUID v4, UUID v7, ULID, or Nano ID values in bulk with one click.
Inspect mystery identifiers from logs, payloads, or CSV exportsvalidate UUIDs and ULIDs, detect versions, and decode timestamps from sortable IDs.
Compress and convert images for web performancereduce file size, convert to WebP or AVIF, resize for social or OG images, and fix Lighthouse next-gen format warnings — all locally in the browser.
Inspect and strip hidden metadata from imagesdetect GPS coordinates, device details, and author info embedded in photos, then export a clean copy without uploading the file anywhere.
Convert text to the right case format or clean messy pasted contenttransform titles, headings, and variables to Title Case, camelCase, snake_case, or any other format, and remove duplicates, blank lines, and stray HTML in one step.
Parse, decode, or rebuild a URL with query parametersbreak long or encoded URLs into clean components, edit query parameters live, detect UTM tags, and copy the rebuilt link without sending it to any server.
Inspect a QR code safely before opening the linkdecode QR code images, screenshots, or webcam frames locally, review URL risk signals, and extract Wi-Fi credentials or contact cards without scanning on a phone.

How these tools work

No signup requiredMost tools run locally in your browserNo data stored between sessionsWorks in modern browsersBuilt and maintained by CodeAvaReview outputs before using in production

Frequently asked questions

Viesearch - The Human-curated Search Engine

From quick tools to deeper audits

Website AuditAudit any public URL for SEO signals, security headers, metadata, and crawlability.Code AuditPaste a snippet and check for security smells, hardcoded secrets, and quality issues.ExamplesExplore worked examples showing how to get the most from CodeAva tools and audits.