astrina
No account needed for most of them

All 148 utilities

77 of them run entirely in your browser — nothing is uploaded and nothing is counted.

148utilities
77run in your browser
32also over the API
9categories

SEO 24

What search engines see, and what stops them.

Full site auditTechnical, speed and security in one pass. API SERP previewHow the snippet looks in search results. API Open Graph previewThe card shown when your link is shared. API Schema validatorValidates JSON-LD structured data. API Meta tag checkerTitle, description and og tags with lengths. API Keyword analysisDensity and frequency of words on the page. API Redirect checkerFollows 301/302 chains hop by hop. API Sitemap checkerValidates the XML sitemap and its index. API HTML validationStructural errors against W3C rules. API robots.txt analyserParses the file and resolves it per crawler. API Image checkerAlt text, dimensions and formats. API Broken imagesCrawls the site for images that fail to load. Account CMS detectorIdentifies the CMS and technology stack. API Readability analysisText difficulty and readability metrics. API Web VitalsLCP and CLS measured in a real browser on a throttled mobile profile, with TTFB and the render-blocking resources behind them. INP needs real visitors clicking, so that one still comes from Search Console. Hreflang checkerInternational markup, including return links. API Link analyserInternal, external and nofollow links. API Canonical checkerWhich URL the page declares as original. API robots.txt generatorBuild the file with a visual editor. ⚡ FAQ schema generatorFAQPage JSON-LD from questions and answers. ⚡ Broken linksFinds 404s, network errors and redirects. Account Server response checkerBulk HTTP codes and redirects. API Favicon checkerEvery size and format a browser looks for. API AI competitor analysisReads a rival page and says where you are behind. Counts are measured; there is no invented score, because a number a model made up would borrow the credibility of the ones we did measure. Pro

Security 13

Certificates, DNS, headers and mail authentication.

Password strengthComplexity and time to crack. Stays local. ⚡ SSL checkerCertificate, chain and expiry. API Security headersHSTS, CSP, frame options, graded. API HTTP headers analyserEvery response header, explained. API CSP analyserNames the directives that leave a hole. API DNS lookupA, AAAA, MX, NS, TXT, SOA and CAA. API WHOIS lookupRegistrar, dates and nameservers. API Email deliverabilitySPF, DKIM and DMARC records. API HTTP/2 and BrotliWhich protocol and compression is used. API IP infoGeolocation and network for an address. API Open portsWell-known service ports, checked safely. API Cookie analyserCookies and their flags against GDPR. API CORS checkerWhich origins your endpoint allows. API

Monitoring 4

Checks that keep running after you close the tab.

Uptime monitorAvailability checked around the clock. Account SEO monitorDaily tracking of SEO signals. Account SSL monitorWarns before the certificate expires. Account Weekly SEO reportAn automatic audit every week. Account

AI 23

Drafts and analysis, metered on your AI allowance.

AI regex generatorA pattern from a description. Account AI social postsPosts sized for Telegram, VK, Instagram. Account AI content planA publishing calendar for a blog. Account AI image generatorImages generated from a prompt. Pro AI meta tag generatorTitles and descriptions that fit. Account AI Schema.org generatorJSON-LD markup for the page. Account AI copywriterA draft article from a brief. Account AI rewriterRephrase and improve a text. Account AI photoreal generatorPhotorealistic image generation. Pro Background removalTransparent PNG from any photo. Pro Upscale 4xFour times the resolution. Pro Background replacementReplace a background by description. Pro Object removalRemove objects by AI inpainting. Pro AI alt textSEO alt text for every image. Account AI headlinesTen H1 variants for one page. Account AI summaryAn article in one to five paragraphs. Account AI FAQ generatorQuestions plus the JSON-LD schema. Account AI tags and keywordsTags, keywords and hashtags. Account AI portraitA realistic portrait from your photo. Business AI text to speechText read aloud in several voices. Pro AI transcriptionAudio turned into text. Pro AI translatorTranslation into the selected language. Account AI paraphraserRephrase to simplify or vary. Account

Originality 6

Was it copied, and was it written by a machine? Measured, with the evidence shown.

Text uniqueness checkFinds the pages that already carry this wording, and what share of your text they cover. Every match is a page we downloaded and compared, not a search result we trusted. AI text detectorScores every sentence against a language model — how predictable each word was, and how far the writing steps off the model's expectations. Probabilistic, and honest about it. Image uniqueness checkFingerprints the picture (pHash/dHash) and looks for the same or a near-identical one already published, including stock-library traces. De-AI text rewriterRewrites a draft so it stops reading as machine-written: stock transitions cut, rhythm varied, over-used words replaced — then measured again with the same detector to prove it worked. De-AI image recoderRe-codes a generated picture so its pixels behave like a photograph — crop, resample, sensor-matched grain, camera-like encoding — and hands the file back. AI image detectorReads provenance metadata (C2PA, generator tags, camera EXIF) and, when that has been stripped, the sensor-level forensics of the pixels themselves.

CSS 21

Build the rule by looking at it.

Border radius generatorVisual CSS border-radius builder. ⚡ Palette from an imageExtract a colour palette from a picture. ⚡ Clip-path generatorVisual CSS clip-path builder. ⚡ Glassmorphism generatorFrosted-glass effect in CSS. ⚡ CSS filter playgroundInteractive CSS filter sandbox. ⚡ CSS ↔ SCSS converterConvert between CSS and SCSS. ⚡ px ↔ rem converterPixels to rem and em, with a table. ⚡ Specificity calculatorWhy one selector beats another. ⚡ Typography scaleGenerate a modular type scale. ⚡ Flexbox playgroundInteractive CSS Flexbox sandbox. ⚡ CSS Grid generatorDraw the grid, take the CSS. ⚡ CSS → TailwindConvert declarations to utility classes. ⚡ HTML → ReactTurn markup into a JSX component. ⚡ Gradient generatorLinear, radial and conic gradients. ⚡ Box shadowStack multiple shadows visually. ⚡ Colour converterHEX, RGB, HSL, HWB, LAB and OKLCH. ⚡ Colour contrastWCAG AA and AAA for normal and large text. ⚡ Palette from a websiteThe colours a site actually uses. API CSS sprite generatorCombine images into one sheet. ⚡ Design token generatorTokens as CSS, JSON, SCSS or Tailwind. ⚡ Responsive testerPreviews at phone, tablet and desktop widths from a real browser, and whether the page actually fits each screen — plus the viewport tag, media queries and breakpoints from the CSS.

DevOps 24

Convert, validate and inspect. Nothing is uploaded.

JSON formatterFormat and validate JSON. ⚡ Regex testerTest regular expressions with groups. ⚡ JWT decoderDecode and inspect a JWT. Stays local. ⚡ Diff checkerCompare two texts line by line. ⚡ .htaccess generatorApache rules for redirects and caching. ⚡ Nginx generatorA server block with TLS and compression. ⚡ Docker Compose builderCompose a stack and copy the YAML. ⚡ Code minifierMinify CSS and JavaScript. ⚡ PHP formatter and syntax checkFormats PHP and reports syntax errors. Nothing is executed — see the note on the tools page. ⚡ PHP versionDetect the PHP version a server reveals. API Markdown previewLive Markdown rendering. ⚡ Cron generatorBuild a schedule and read it back. ⚡ CSV ↔ JSONConvert between CSV and JSON. ⚡ YAML ↔ JSONConvert between YAML and JSON. ⚡ SQL formatterFormat and minify SQL. ⚡ XML formatterFormat, minify and validate XML. ⚡ URL parserSplit a URL into its components. ⚡ Escape / unescapeHTML, JSON, JS, URL and Base64. ⚡ JSON Schema validatorValidate a document against a schema. ⚡ Cron parserExplain a cron schedule in words. ⚡ JSONPath testerExtract data from JSON by path. ⚡ TOML ↔ JSONConvert between TOML and JSON. ⚡ PEM viewerInspect certificates, keys and CSRs. ⚡ GraphQL formatterFormat and minify GraphQL. ⚡

Utilities 32

Everyday tools that run in your browser.

Password generatorStrong passwords, generated locally. ⚡ QR generatorAny text or link as a QR code. ⚡ Favicon generatorEvery favicon size from one image. ⚡ Image compressorJPG, PNG and WebP with a quality control. ⚡ SVG encoderSVG to base64 and data URI. ⚡ Base64 encoderEncode and decode Base64. ⚡ URL encoderPercent-encode and decode. ⚡ TransliterationCyrillic to Latin and a URL slug. ⚡ TimestampUnix time to a date and back. ⚡ Lorem IpsumPlaceholder text in any quantity. ⚡ Word counterWords, characters and sentences. ⚡ EmojiSearch and copy emoji. ⚡ Screenshot toolFull-page capture of any public page in a real browser, scrolled first so anything that loads on scroll is in the picture. Account Case converterChange text case in every convention. ⚡ Hash generatorSHA-1, SHA-256 and SHA-512. ⚡ UUID generatorUUID v4 and v7 in bulk. ⚡ Image resizeResize images in the browser. ⚡ Reading timeHow long an article takes to read. ⚡ Text sortingSort lines and remove duplicates. ⚡ Unit converterLength, weight, temperature and volume. ⚡ Image converterPNG to JPG, WebP and other formats. ⚡ Image cropCrop with an aspect ratio. ⚡ Find and replaceBulk replace, with regular expressions. ⚡ Barcode generatorEAN-13, Code128 and Code39. ⚡ QR decoderRead a QR code from an image. ⚡ Random dataNumbers, strings, UUIDs, emails, names. ⚡ Timezone converterThe same moment across zones. ⚡ StopwatchLaps and split times. ⚡ Classic ciphersCaesar, ROT13, Vigenère, Atbash, Base64. ⚡ HTML entitiesEncode and decode HTML entities. ⚡ CSV validatorCheck the structure of a CSV file. ⚡ Lorem Ipsum advancedLatin, Russian, HTML and Markdown. ⚡

Design 1

Colour, picked precisely.

Colour pickerPick a colour and read HEX, RGB, HSL, HSV. ⚡

How the plans divide these up.

Opening a tool is not what costs us anything — volume is. Every tool that runs in your browser is free to everyone, forever, with no counter. What the plan decides is how much one run may cover, how many server-side runs you get a day, and whether results are kept, exported, scheduled or reachable from the API.

  • We do not run other people’s code. One tool on comparable lists is an online PHP editor that executes what you paste; Astrina formats PHP and reports syntax errors, and nothing is ever executed.
  • Tools that fetch a page identify themselves honestly and obey robots.txt.
  • Anything processed in your browser stays there — files are never sent to us.
See the table → API access

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