All tools

Waveform generatorA clean waveform image from any audio file, sized for a post or a player.

Audio file inspectorDuration, channels, sample rate, peak level and the real bitrate.

Trim audioCut to a start and end point, exact to the millisecond.

Normalize audioBring the loudest peak to a target level without clipping anything.

Volume changerRaise or lower the level by a set amount, with clipping reported honestly.

Silence removerStrip the dead air from the start and end of a recording.

Sample rate converterMove between 48 kHz, 44.1 kHz and lower rates for voice.

Merge audioJoin clips end to end in the order you drop them, with an optional crossfade.

Extract audio from videoPull the soundtrack out of a video without uploading the video.

Audio size calculatorWhat a recording will weigh at a given bitrate, length and channel count.

Cron builderBuild the expression from plain fields, and see the next five runs before you ship it.

Cron explainerRead a five-field schedule back in plain English before it goes live.

cURL builderAssemble a request from method, headers and body, and copy a command that works.

cURL to codeTurn a cURL command into fetch, requests, net/http or reqwest.

Webhook payload inspectorFormat a payload and see its shape — every key, its type and where it nests.

HTTP status explainerWhat a status code means, what usually causes it, and what to do next.

Response header readerPaste response headers and read what they say about caching, security and cookies.

User-agent parserBrowser, engine, platform and device, read out of a user-agent string.

MIME type lookupThe right Content-Type for a file extension, and what an unfamiliar type means.

Percentage calculatorPercent of a number, change between two numbers, and the reverse.

Aspect ratio calculatorScale a width or height and keep the ratio exact, with the simplified form.

Download time calculatorHow long a file takes on a given connection, and the other way round.

Data size converterConvert between bytes, kibibytes and the decimal units marketing uses.

Loan & EMI calculatorMonthly instalment, total interest and the full cost of borrowing.

Date differenceDays, weeks and working days between two dates, inclusive or not.

Tip & bill splitTip, total and the per-person share, rounded the way people actually pay.

Discount calculatorSale price, money saved, and what a stacked second discount really costs.

VAT & sales taxAdd or strip tax at any rate, and see the net, tax and gross split out.

BMI calculatorBody mass index in metric or imperial, with the category it falls in.

Age calculatorExact age in years, months and days, plus the next birthday countdown.

Unit converterLength, weight, temperature and volume, metric and imperial both ways.

Roman numeralsConvert in both directions, with the subtractive rules applied properly.

Compound interestWhat regular saving becomes, and how much of it is growth rather than deposits.

Colour converterOne colour in every notation at once, with a WCAG contrast check.

Palette generatorHarmonies, tints and shades from one base colour, with the hex codes ready to copy.

CSS gradient generatorLinear and radial gradients with a live preview and the exact CSS to paste.

Box shadow generatorOffset, blur, spread and colour, previewed on a real card as you tune it.

Contrast checkerTwo colours, one ratio, and a straight answer on whether it passes AA and AAA.

Tailwind colour finderThe nearest Tailwind class to any hex value, with the distance so you can judge it.

Colour blindness simulatorSee a design the way eight percent of men do, before you rely on red and green.

CSV to JSONHeaders become keys, with types guessed sensibly and quotes handled properly.

JSON to CSVFlatten an array of objects into a spreadsheet-ready table.

CSV viewerRead a messy CSV as an aligned table, with the row and column counts confirmed.

CSV cleanerDrop duplicate rows, trim every cell and remove the empty columns Excel leaves behind.

CSV sorterSort by any column, as text or as numbers, header row kept in place.

CSV to SQLINSERT statements with values quoted and escaped the way the database expects.

JSON to YAMLReadable YAML with proper indentation, for config files and CI pipelines.

YAML to JSONTurn a config file back into JSON, with the limits stated rather than guessed.

JSON Lines converterBoth directions, for log pipelines and bulk import formats that need one object per line.

JSON formatter & validatorPretty-print, minify and validate, with the error line called out plainly.

Base64 encoder & decoderBoth directions, UTF-8 safe, with URL-safe variants covered.

URL encoder & decoderPercent-encode a whole URL or just a component, and read it back.

Hash generatorDigest any text locally with the browser crypto engine.

UUID generatorCryptographically random identifiers, as many as you need at once.

JWT decoderRead the header and payload of a token without sending it anywhere.

HTML entity encoderEscape markup for safe embedding, or turn entities back into characters.

Timestamp converterEpoch seconds or milliseconds to a readable date, and the other way round.

Markdown to HTMLHeadings, emphasis, links, lists and code turned into clean markup.

CSS minifierStrip comments and whitespace, and see exactly how many bytes you saved.

HTML minifierCollapse the whitespace a template engine leaves behind, safely.

Regex testerMatch counts, capture groups and the matched text, as you type the pattern.

URL parserBreak a URL into its parts and read the query string as a table.

Text diffLine-by-line comparison with additions and removals marked in place.

JSON to typesGenerate TypeScript interfaces, Rust structs, Go structs or Python dataclasses from a payload.

JSON tree viewerThe shape of a payload as an outline, with every value and its type.

SQL formatterReadable indentation and keyword casing for a query you inherited.

Compress image to exact sizeName a limit in KB or MB. Get the best-looking file that fits under it.

Resize image to exact dimensionsPixel-exact width and height, with sensible cropping and no upscaling surprises.

Image format converterConvert in both directions, with quality control.

Rotate & flipStraighten a scan or mirror a photo without re-encoding more than once.

Blur & pixelateCover faces, plates or account numbers before you share a screenshot.

Add watermarkText watermark with opacity, position and size, on one image or a whole batch.

Colour palette extractorPull the dominant colours out of an image as HEX, RGB and HSL.

Favicon generatorEvery size a browser asks for, plus the manifest entries, from one square image.

Image to PDFTurn a stack of photos or scans into one paginated PDF, in the order you choose.

Crop imageFixed-ratio crops with the presets social platforms and ID forms expect.

Enlarge imageScale up to 2×, 3× or 4× with smoothing, for print or a bigger frame.

Photo filtersGrayscale, sepia, brightness, contrast and saturation, applied in one pass.

Add a borderA clean frame in any colour and thickness, sized in percent so batches match.

Round the cornersRounded or circular crops with real transparency, for avatars and cards.

Caption an imageTop and bottom captions in the classic style, with an outline that stays readable.

Compress PDF to exact sizeBring a PDF under an upload cap while keeping the text readable and selectable.

Merge PDFCombine documents in any order, drag to rearrange before you export.

Split PDFPull out a page range, or break one file into single-page documents.

PDF to imagesRender pages to images at a resolution you pick, one file per page.

Delete pagesDrop the blank scans and cover sheets, keep everything else untouched.

Extract textCopy out the text layer of a PDF, with page breaks preserved.

Protect PDFSet an open password and decide what recipients may print or copy.

Unlock PDFRemove a password you already know, so the file opens without one.

Watermark PDFStamp text across every page, at the opacity and angle you choose.

Add page numbersNumbers in any corner, starting wherever your document actually starts.

Rotate PDFTurn every page, or just the landscape ones, the right way up.

Organise pagesReorder, duplicate and drop pages, then export the arrangement you built.

PDF to WordAn editable document that keeps headings, lists and tables where they were.

Word to PDFA PDF that looks the same on every machine, fonts included.

OCR a scanTurn a picture of words into words you can search, select and copy.

Repair PDFRebuild a damaged cross-reference table so a broken file opens again.

Strip image metadataRemove EXIF, GPS and camera data by re-encoding the pixels only.

What your image revealsSee which metadata blocks a photo carries before you post it anywhere.

Password generatorLong random passwords or passphrases, generated on your device only.

Redact a screenshotPixelate the whole image or bands of it, so nothing readable survives.

Password strengthHow long a password would really hold up, checked entirely on your device.

Test data generatorInvented names, emails and addresses for testing, so no real person is exposed.

Meta tag generatorTitle, description, canonical, robots, Open Graph and Twitter tags in one block.

SERP previewSee your title and description the way a search result will show them, truncation included.

Social card previewSee the title, description and image a shared link will carry, drawn at the documented card sizes.

Robots.txt generatorCrawl rules that say what you mean, with the AI crawlers handled explicitly.

Sitemap generatorPaste a list of URLs and get a valid sitemap, with priorities and change frequency.

Schema markup generatorArticle, FAQ, Product, LocalBusiness and Breadcrumb structured data, filled in and valid.

Hreflang generatorLanguage and region tags that point at each other properly, x-default included.

llms.txt generatorTell AI crawlers what your site is and which pages matter, in the emerging format.

Keyword densityWhat a page is actually about, by term and phrase, with filler words discounted.

Heading outlineThe document outline a crawler sees, with skipped levels and duplicate H1s flagged.

Alt text checkerEvery image in your markup, and which ones are missing or wasting their alt text.

Canonical URL cleanerStrip tracking parameters and normalise a URL to the one version you want indexed.

UTM link builderCampaign links with consistent, lower-case parameters that will actually group in reports.

UTM link readerRead a campaign link back as a table, and spot the inconsistent casing.

Robots.txt testerPaste your rules and a path, and see which directive wins and why.

Draw your signatureSign with a finger, trackpad or mouse and get a transparent PNG to reuse.

Sign a PDFPut your signature, your initials and the date on any page, wherever you choose.

Request a signatureMark the fields each signer must fill, then send the document for signing.

Case converterSentence, title, upper, lower, camel, snake and kebab, in one pass.

Word & character counterWords, characters, sentences, paragraphs and reading time as you type.

Find & replacePlain or regular-expression replacement across the whole document.

Sort & dedupe linesAlphabetical, reverse or by length, with duplicate removal.

Whitespace cleanerStrip double spaces, trailing whitespace and stray blank lines.

Slug generatorURL-safe slugs with accents folded and separators of your choosing.

Lorem ipsum generatorPlaceholder paragraphs, sentences or words, in classical or plain English.

Reverse & flip textReverse characters, words or line order for quick sanity checks.

Word frequencyWhich words you lean on, ranked, with filler words filtered out.

Readability scoreReading ease and the school grade your draft currently demands.

Remove accentsFold accented characters to plain ASCII for slugs, filenames and legacy systems.

Caesar cipherShift the alphabet by any amount, ROT13 included. Fun, not security.

Text to binaryBoth directions, in binary, octal, decimal or hex, byte by byte.

Morse codeEncode and decode, with the spacing convention operators actually use.

Video file inspectorReal resolution, duration, aspect ratio and the bitrate it actually uses.

Video thumbnail grabberA still from any point in the clip, at full frame resolution.

Frame extractorA strip of evenly spaced frames, zipped up — for contact sheets and storyboards.

Thanks to you,ToolZool stays free

Thanks to you,
ToolZool stays free