Free tools that never see your files.

HEIC, JPG, PNG, WebP, AVIF, RAW and 25 more. 264 pairs.

Smaller file, keeping the quality that actually matters.

The best quality per byte, tuned for each format.

Exact pixels, aspect ratio locked.

Compare codecs head to head on your own machine.

What image formats THIS browser actually decodes — measured, not a compatibility table.

Words, characters, graphemes, sentences, lines, and bytes — counted by the same rules every time.

One text in, fourteen casings out — camel, snake, kebab, and more.

Render Markdown to HTML, convert HTML back — with a DOMPurify-sandboxed preview.

CSV, TSV, or pipe text in — an aligned GFM table out, pipes escaped.

Every code point with bytes, escapes, entities, and normalization forms.

Undo UTF-8-read-as-windows-1252 garbling — verified by byte round-trip, never guessed.

GSM-7 or UCS-2, parts, and characters left — the 3GPP TS 23.038 math.

Sort, dedupe, trim, filter, renumber — deterministic cleanup with a changelog.

HEX, RGB, HSL, and HSV from one color, plus the WCAG contrast ratio against another.

Length, mass, temperature, data, and more — one value in, every unit out, reference conditions stated.

Decimals to fractions and back — exact rationals, mixed numbers, repeating decimals marked.

Mean, median, mode, variance, deviation, quartiles — paste numbers, get every measure.

Primality, factorization, next/previous prime, ranges, and multi-number GCD/LCM — exact BigInt.

Exact aspect ratios, resize targets that lock the ratio, PPI from real dimensions, print sizes.

Test a regular expression against your own text — the browser’s own engine, in a disposable worker.

Explain a cron schedule in plain English and list its next fire times, dialect and timezone explicit.

Sort versions, compare two, and match ranges — strict SemVer 2.0.0, coercion shown separately.

Test glob patterns against a list of paths — picomatch in a bounded worker, dialect explicit.

Encode and decode, with a URL-safe alphabet option.

Percent-encode components or whole URIs, and back.

Image files to data URLs and back — format read from bytes, dimensions decoded, nothing re-encoded.

Properly random, with an honest strength meter.

API keys, hex secrets, nanoids, and sortable ULIDs — CSPRNG, entropy stated.

RFC 9562 UUIDs — v1, v3, v4, v5, v6 and v7.

SHA-2, SHA-3, Keccak, BLAKE and legacy checksums, for text or files.

Score a password with zxcvbn — the guessing model, with matched patterns shown.

Keyed MACs over text — SHA-1/256/384/512 through WebCrypto, keys as text/hex/base64.

Hash with bcryptjs cost 4–15 in a disposable worker; verify against a pasted hash.

Pretty-print or minify, sort keys, and validate.

Check strict JSON or JSONC, then explore it as a tree.

Sort object keys — top level or every level.

Escape raw text into a JSON string body, and back.

Pull values out with JSON Pointer or a JSONPath subset.

Semantic and text comparison of two documents, with an RFC 6902 patch export.

Convert JSON to and from YAML, TOML, CSV, XML, NDJSON, query strings, .env, MessagePack, CBOR, and BSON.

Generate TypeScript, Go, Rust, and Zod from JSON.

Validate JSON against a JSON Schema — 2020-12, 2019-09, or draft-07 — with every rule stated up front.

Inspect headers and claims; verify signatures with a local key.

RFC 6238 codes from an authenticator secret — plus code verification with clock-drift window.

Generate an RFC 7636 verifier/challenge pair, or check a pair against each other.

Hash a script or stylesheet into an integrity= attribute — text or file.

Parse an Authorization header — Basic decodes, Bearer shape-checks, Digest splits.

Evaluate a Content Security Policy with csp_evaluator — or build one, finding by finding.

Read a SAML response — fields, attributes, conditions — and check its signature.

X.509 certificates and CSRs — subject, SANs, validity window, key facts.

Inspect a JSON Web Key or JWKS — members, thumbprint, PEM form.

Inspect and format .env files — duplicates, exports, quoting rules named.

Parse INI — sections, dotted paths, boolean coercions, last-wins duplicates.

Java properties — dotted keys, escapes decoded, comments counted.

Octal ⇄ symbolic permission modes, special bits named for what they do.

Paste CSV, get INSERT statements — quoted per standard SQL, NULLs by your choice.

Turn a docker run command into a compose service — unmapped flags listed, never dropped.

Every identity field your browser volunteers — read live in this tab, caveats included.

Paste any user-agent string, see the browser, engine, OS, and device it claims.

Which APIs this browser has — presence measured, permissions only queried, never asked.

A dated web-platform snapshot checked live — where this browser agrees, leads, or lags.

Screen, DPR, layout and visual viewports, orientation, preferences — live, fingerprinting labeled.

Fonts, codecs, WebGL/WebGPU, storage, permissions — the five probes that need real work.

See yourself, read the track's real settings, switch cameras — permission only on your click.

A live level meter over the real stream — nothing recorded, permission only on your click.

Left, right, both — three synthesized tones; your ears do the checking.

Press keys in the zone — see key, code, location, and modifiers exactly as the browser sees them.

Buttons with real names under standard mapping, live axes, an explicit vibration pulse.

Five solid colors, full screen — your eyes are the detector, and the page says so.

A four-second frame-timestamp sample — median-interval Hz with every caveat kept honest.

Record your screen, a window, or a tab — permission on your click, every resource released on stop, output verified.

Network, broadcast, mask, wildcard, host counts — exact BigInt math on your CIDR.

Expand, compress, and canonicalize IPv6 — RFC 5952 rules applied and named.

First and last address, exact 2^n capacity, arpa prefix — for any /0–/128.

Private, reserved, or special-purpose — checked against a dated IANA registry snapshot.

IPv4/IPv6 as integer, hex, and binary — exact both directions.

Allocate unequal subnets from one base — every sizing decision visible as a step.

Split a block into equal children, or merge siblings back — preconditions refused honestly.

Every MAC notation, the U/L and group bits named, the EUI-64 and its fe80:: derivation.

A dated, curated IANA port snapshot — search numbers, names, and protocols.

Transfer time at a line rate — exact fractions, both unit bases, no fake efficiency.

Count and inspect OpenAI tokens — o200k, cl100k, p50k, r50k, in a worker.

Does your prompt fit? Exact OpenAI counts; labeled estimates for any other model.

What a prompt costs to run — dated price data, exact arithmetic, tiers applied.

Validate and format training files — target presets, per-line errors, loss ledger.

Read a ChatGPT export or JSONL log — virtualized, local, nothing sent anywhere.

Render a transcript to ChatML, Llama, Mistral, or Gemma format — with token counts.

Every twilight phase of one day — dawn to dusk, on the place's own clock.

Golden and blue hour windows — altitude-crossing boundaries, durations included.

Illumination, named phase, moonrise and moonset, and the next new and full moons.

Page count, page sizes, metadata, and which pages carry text — read from structure, nothing rendered.

Extract, delete, or rotate pages by an explicit spec — output re-loaded and verified before download.

List ZIP contents without inflating them — sizes, ratios, traversal flags — extract single entries or build a new archive.

See what a photo discloses — GPS, device, dates, software — then re-encode it clean, verified.

Read TTF, OTF, and WOFF files — names, metrics, glyph count, tables, axes — with a sandboxed sample outline.

Disclose what an SVG carries — scripts, handlers, external refs — then get a copy that cannot fetch or run anything.

Fake names from a locale’s own pools — first, last, and full — seeded so every list reproduces.

Fake street, city, region, postcode, and country rows in the locale’s pattern — shapes for tests, never locations.

Phone numbers that match a locale’s pattern — for form tests, with no live/dead claim anywhere.

Whole fake people — name, username, example-domain email, phone, birthday, job, address — one seeded row.

Invented company names with catch phrase and buzz phrase — fixture businesses matching no registry.

Thousands of fake rows for tests — pick columns, lock a seed, export JSON, JSONL, or CSV.

A scannable QR code for any link or text — PNG or SVG, in your browser.

Unix to ISO 8601 and back, with relative time.

One moment across every zone, laid out side by side.

Milliseconds up to weeks, with a human breakdown.

Share free slots by link. No calendar connection.

Add durations to a date and diff two dates — wall-clock vs elapsed across DST, both stated.

Gregorian ⇄ Hijri, Hebrew, Persian, Chinese, and eleven more — your browser's ICU tables.

Every time utility in one place. No files needed.