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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Why Your CSV Opens as Mojibake in Excel

The file isn't corrupted. Excel guessed the wrong encoding, and a CSV carries no field that could have told it the right one.

Why Money Math Breaks in Floating Point

0.1 + 0.2 isn't 0.3 because binary can't write one tenth. The same limitation puts a stray cent in payroll totals and amortization schedules.

Why Trimming a Video Re-Encodes the Whole Thing

Video frames mostly store differences from other frames, so cutting anywhere but a keyframe means the codec has to rebuild everything after the cut.

Sample Rate and Bit Depth, Without the Myths

Sample rate sets the highest frequency you can record; bit depth sets the noise floor. Neither one works the way "higher is smoother" suggests.

The Same Korean Text, Two Different Byte Sequences

Unicode can spell 한 as one code point or three. Both are correct, they look identical, and string comparison treats them as different text.

How a Scratched QR Code Still Scans

QR codes carry redundant data computed with Reed–Solomon coding, which is why a torn corner or a logo pasted in the middle usually doesn't stop them.

Everyday Essentials

Short links, JSON, timestamps — the utilities you reach for daily

URL Shortener

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

JSON Formatter & Viewer

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

Timestamp Converter

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

Calculators

Percentage, loan, age, BMI, dates — everyday calculators

Percentage Calculator

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

Loan Calculator

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

BMI Calculator

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

Unit Converter

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

Age Calculator

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

Date Difference Calculator

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

Image Core

Resize, compress, convert, split — safely in your browser

Image Splitter & Cropper

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

Image Resize

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

Image Rotate

Rotate an image 90, 180, or 270 degrees.

Image Flip

Flip an image horizontally or vertically.

Image Grayscale

Convert a color image to black and white.

Batch Resize & Watermark

Resize many images at once and add watermarks.

Background Remover

Remove image backgrounds automatically with AI.

Image Compressor

Shrink image file size without losing quality.

Image Converter

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

Photo Merger

Merge multiple photos into one.

Text Overlay

Add text and captions over images.

JPG to PNG

Convert JPG to PNG instantly.

HEIC to JPG

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

Remove White Background

Make white backgrounds transparent.

Compress Image to 100KB

Compress any image to under 100KB precisely.

EXIF / Metadata Remover

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

Spell Chain (Flow)

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

SVG to PNG

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

Media & Document

GIF, video, audio, PDF — convert and edit

GIF Tools

Make, edit and optimize GIFs.

Video Converter

Convert between video formats.

Video Editor

Trim and edit video in your browser.

Audio Converter

Convert between audio formats.

Audio Size Reducer

Compress audio file size.

Screen Recorder

Record your screen from the browser.

PDF to Image

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

Merge & Split PDF

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

Image to PDF

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

Compress PDF

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

Unlock PDF

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

Protect PDF

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

Survey Maker

Create surveys & forms fast with Google Forms.

Maker & Dev

Sprites, tilemaps, fonts, calculators — tools for makers

Sprite Generator

Generate sprite sheets for games.

Sprite Analyzer

Analyze and slice sprite sheets.

Bitmap Font Generator

Generate bitmap fonts for games.

Pixel Sound Generator

Generate retro 8-bit sound effects.

Seamless Texture

Generate tileable seamless textures.

Developer Calculator

Base conversion and bitwise calculator.

JS Bundler

Bundle JavaScript in the browser.

Markdown Viewer

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

Markdown Editor

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

Guide Hub

Guides and how-tos for every tool.

JWT Decoder

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

UUID Generator

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

Text Diff / Compare

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

Password Generator

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

Base64 Encode / Decode

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

Case Converter

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

Lorem Ipsum Generator

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

Regex Tester

Test regular expressions live with match highlighting and capture groups.

SQL Formatter

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

CSV ↔ JSON Converter

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

Korea Tools

Char/byte counter, IME fixer, Korean age, pyeong, net salary — built for Korea

Character & Byte Counter

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

Korean IME Fixer (한영타)

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

Korean Age Calculator

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

Pyeong ↔ m² Converter

Convert between Korean pyeong (평) and square meters.

Net Salary Calculator (KR)

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

Meeting Point Finder

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

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.