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Spellkit
77 free tools · no install, no sign-up

Every tool you need, in one place

No installs, no sign-up — just open a tool and go. Your files stay on your device, so you can use it with peace of mind.

From the blog

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How to Combine Photos Without Distorting Them

Merging two photos forces decisions about aspect ratio, resolution, and layout — and the wrong default (stretching) is the one mistake viewers always notice.

How Text Diffs Actually Work

A diff tool doesn't watch you edit — it computes the smallest set of deletions and insertions that turns one text into the other, which explains a lot.

Why Markdown Won

Markdown beat richer markup formats by optimizing for one thing — being readable as plain text before any rendering — and that explains its gaps too.

What MP3 Actually Throws Away (and When WAV Still Matters)

WAV stores every sample of the raw signal; MP3 and AAC permanently discard the parts a psychoacoustic model predicts you can't hear.

The Five UTM Parameters, and How They Go Wrong

UTM tags are plain query parameters that analytics tools group into reports — so every typo, casing difference, and misplaced link shows up forever.

How Instagram Grid Posts Actually Work

A grid mural is one wide image cut into equal slices and uploaded in reverse order — the hard parts are the crop math and the profile grid's aspect ratio.

Everyday Essentials

URL Shortener

Turn long links into short, clean URLs — with auto OG preview cards.

Open

JSON Formatter & Viewer

Pretty-print, validate, and explore JSON as a tree. All in your browser.

Open

Timestamp Converter

Convert Unix timestamps ↔ dates both ways. Milliseconds and timezones supported.

Open

Calculators

Percentage Calculator

Find X% of a number, what percent one value is of another, and percent change.

Open

Loan Calculator

Monthly payment, total interest, and a full amortization schedule for any loan.

Open

BMI Calculator

Body Mass Index and weight category from height and weight — metric or imperial.

Open

Unit Converter

Convert length, weight, temperature, volume, area, and speed units instantly.

Open

Age Calculator

Your exact age in years, months and days — plus total days and next birthday.

Open

Date Difference Calculator

Days, weeks, and the exact years/months/days between any two dates.

Open

Image Core

Image Splitter & Cropper

Split an image into a grid or crop a region, then download as ZIP. No upload, fully private.

Open

Image Resize

Resize an image by width or height, right in your browser.

Open

Image Rotate

Rotate an image 90, 180, or 270 degrees.

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Image Flip

Flip an image horizontally or vertically.

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Image Grayscale

Convert a color image to black and white.

Open

Batch Resize & Watermark

Resize many images at once and add watermarks.

Open

Background Remover

Remove image backgrounds automatically with AI.

Open

Image Compressor

Shrink image file size without losing quality.

Open

Image Converter

Convert between PNG, JPG and WebP, right in your browser.

Open

Photo Merger

Merge multiple photos into one.

Open

Text Overlay

Add text and captions over images.

Open

JPG to PNG

Convert JPG to PNG instantly.

Open

HEIC to JPG

Convert iPhone HEIC photos to JPG/PNG — in your browser.

Open

Remove White Background

Make white backgrounds transparent.

Open

Compress Image to 100KB

Compress any image to under 100KB precisely.

Open

EXIF / Metadata Remover

Strip EXIF, GPS location and other metadata from photos — no quality loss. In your browser.

Open

Spell Chain (Flow)

Chain image tools into one pipeline and run them in a single pass — saved in your browser.

Open

SVG to PNG

Convert SVG to PNG at any size — scale, width, or height, keeping transparency.

Open

Layout & Social

Combine 2 Photos Side by Side

Place two photos next to each other.

Open

Instagram Grid Splitter

Split an image into an Instagram 3x3 grid.

Open

Design Editor

A simple graphic design editor.

Open

Page Builder

Build landing pages without code.

Open

Link Generator

Generate UTM, deep links and more.

Open

QR Code Generator

Turn URLs and text into QR codes.

Open

App Icon Generator

Generate iOS & Android app icon sets.

Open

Color Palette

Extract colors from images and build palettes.

Open

YouTube Thumbnail Downloader

Download YouTube thumbnails in HD.

Open

YouTube Comment Picker

Pick random winners from YouTube comments.

Open

Favicon Generator

Turn an image into a favicon.ico, apple-touch icon and manifest bundle.

Open

Media & Document

GIF Tools

Make, edit and optimize GIFs.

Open

Video Converter

Convert between video formats.

Open

Video Editor

Trim and edit video in your browser.

Open

Audio Converter

Convert between audio formats.

Open

Audio Size Reducer

Compress audio file size.

Open

Screen Recorder

Record your screen from the browser.

Open

PDF to Image

Convert each PDF page to a PNG/JPG image — in your browser.

Open

Merge & Split PDF

Combine PDFs or extract specific pages (not text editing).

Open

Image to PDF

Combine JPG/PNG images into one PDF — reorder pages, pick page size. In your browser.

Open

Compress PDF

Shrink scanned/image PDFs. Pick a quality and download. In your browser.

Open

Unlock PDF

Remove the password from a locked PDF you can open. In your browser.

Open

Protect PDF

Add a password to a PDF so it asks for it on open. In your browser.

Open

Survey Maker

Create surveys & forms fast with Google Forms.

Open

Maker & Dev

Sprite Generator

Generate sprite sheets for games.

Open

Sprite Analyzer

Analyze and slice sprite sheets.

Open

Bitmap Font Generator

Generate bitmap fonts for games.

Open

Pixel Sound Generator

Generate retro 8-bit sound effects.

Open

Seamless Texture

Generate tileable seamless textures.

Open

Developer Calculator

Base conversion and bitwise calculator.

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JS Bundler

Bundle JavaScript in the browser.

Open

Markdown Viewer

Paste or open Markdown (.md) and see it rendered instantly.

Open

Markdown Editor

Write Markdown with live preview; export to .md or HTML.

Open

Guide Hub

Guides and how-tos for every tool.

Open

JWT Decoder

Decode a JWT into header, payload and claims — check expiry. In your browser.

Open

UUID Generator

Generate UUID v4, v7 and v1 in bulk — copy or download.

Open

Text Diff / Compare

Compare two texts line by line — added and removed lines highlighted.

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Password Generator

Create strong random passwords instantly — pick length, character sets, and bulk count.

Open

Base64 Encode / Decode

Encode and decode text to Base64 — Unicode-safe, with a URL-safe option.

Open

Case Converter

Convert text to UPPER, lower, Title, camelCase, snake_case, kebab-case and more.

Open

Lorem Ipsum Generator

Generate placeholder text by words, sentences, or paragraphs — with optional HTML.

Open

Regex Tester

Test regular expressions live with match highlighting and capture groups.

Open

SQL Formatter

Beautify SQL queries per dialect or minify to one line — all in your browser.

Open

CSV ↔ JSON Converter

Convert CSV to JSON and JSON to CSV — headers, delimiters and types handled.

Open

Korea Tools

Character & Byte Counter

Count characters, words, and UTF-8 / EUC-KR bytes in real time.

Open

Korean IME Fixer (한영타)

Fix text typed in the wrong keyboard layout (e.g. dkssud → 안녕).

Open

Korean Age Calculator

Calculate your international (만) age and year age from your birth date.

Open

Pyeong ↔ m² Converter

Convert between Korean pyeong (평) and square meters.

Open

Net Salary Calculator (KR)

Estimate monthly take-home pay after Korean insurance & tax.

Open

Meeting Point Finder

Find the fairest subway station to meet at by transit time — up to 10 people (Korea).

Open

Frequently asked questions

Is Spellkit free?
Yes. Every tool on Spellkit is completely free — no sign-up, no trial, and no usage limits.
Are my files uploaded to a server?
No. Most Spellkit tools run entirely in your browser, so your files and data never leave your device.
Do I need to install anything or create an account?
No installation and no account. Spellkit works instantly in any modern web browser.
Does Spellkit work on mobile?
Yes. Spellkit is fully responsive and works on phones, tablets, and desktops in any up-to-date browser.