Practical how-to articles for image compression, PDF management, AI writing, and developer utilities — written by the ToolsGravity team.
Write in Markdown or HTML and export a polished PDF styled with your own CSS — or turn a fixed PDF into reflowable ePub or one long scrolling page.
Remove blank pages, split one scan into separate files at divider sheets, pull out photos, and auto-rename files so a folder of scans becomes searchable.
Beat email attachment limits, split long PDFs into one file per chapter named after its bookmarks, and add an outline when a PDF has none.
PDFs can carry scripts that run on open and files most viewers hide. How to inspect a PDF before you trust it, sanitize it, and use attachments safely.
Five one-click photo fixes: brighten a flat image, un-mirror a selfie, invert film negatives, tint a mismatched set, and pixelate. Free, no watermark.
Why your logo gets a white box, why the converted file is bigger, and why iPhone photos won’t open on Windows — converting PNG, JPG, WebP and HEIC.
Enlarge small photos without the blur, crop to any aspect ratio without cutting off heads, and check the GPS and camera data hidden in your images.
Four workspaces that replace a drawer of single-purpose tools: a tour of the Text, Dev, Image and PDF Studios — what each does and when to use it.
Convert chmod permissions, look up HTTP status codes and MIME types, make a .gitignore or bcrypt hash, and check WCAG contrast — free, in your browser.
Quick text jobs done instantly: find & replace, line numbers, invisible-character removal, word frequency, and placeholder, fancy or ASCII text. Free.
Draft AI headlines, meta descriptions, tone changes and translations, then check readability and keyword focus before you publish.
Open iPhone HEIC photos anywhere, shrink images with WebP, or keep transparency with PNG. A guide to converting between common image formats, free.
Rotate a sideways page, invert colours for night reading, strip images, remove pages, or inspect a PDF’s properties and scripts — lesser-known free tools.
Build CSS box-shadows, border-radius and easing curves visually, then tidy messy code and convert between JSON, YAML and XML — free, in your browser.
Print several pages per sheet, a folded booklet, a tiled poster, or on a new paper size — a guide to the free PDF print-layout tools.
Add an APPROVED stamp, a logo, letterhead or a repeated header to a PDF without rebuilding it — the free PDF stamp, image and overlay tools.
Unlock a form that won’t let you type, pull the answers out as data, and flatten a finished form so it can’t be changed — the free PDF forms workflow.
Turn images, Word, HTML and Markdown into PDF — and PDF back into Word, PowerPoint, images, HTML, Markdown or EPUB. Every free PDF converter, one guide.
Password-protect, redact and sanitize a PDF before you send it: lock down access, permanently remove sensitive text, and strip hidden metadata.
Low-light photos come out grainy. Where noise comes from, the strength-vs-detail trade-off, and how to denoise a photo free online.
Generate TypeScript interfaces from a JSON API response for autocomplete and type safety — no hand-typing. How it works, with examples, free.
Split a big PDF by chapter or file size, extract a range, reorder pages, or drop blank scanner pages — the free PDF split and organize tools.
The everyday image jobs — resize to exact pixels, smart-crop, rotate, flip, and add a border. A guide to the free image transform tools, all in your browser.
A cron expression schedules recurring jobs in five fields. What each field means, how to read examples like 0 9 * * 1, and how to build your own free.
Decimal, binary, hex and octal: where programmers use each number system, and how to convert between all four instantly, free in your browser.
Turn a JSON array of objects into a clean CSV for Excel, Sheets and imports — one row per object. What converts cleanly, with examples, free.
Text copied from PDFs, emails and web pages arrives messy. Free one-click tools to remove extra spaces, duplicate lines, line breaks, accents and HTML.
Write in Markdown, publish in HTML: how Markdown becomes clean, semantic HTML (and back), with examples — free and live in your browser.
A UUID is a 128-bit unique ID for database keys, request IDs and more. What UUIDs are, how the versions differ, and how to generate v4 UUIDs free.
Free one-click photo effects — blur, sharpen, grayscale, sepia, invert, tint, vignette and pixelate — and exactly when to reach for each one.
What makes a good URL slug — lowercase, hyphenated, keyword-first — and how to turn any title into a clean, SEO-friendly slug, free in your browser.
Turn CSV data into a clean Markdown table for READMEs, docs and GitHub issues, with quotes, commas and alignment handled. With examples, free.
An app or PWA needs its icon in dozens of sizes for iOS, Android and the web. What each platform needs, and how to make the full set from one image.
Dull, flat or slightly dark photo? Auto-enhance fixes exposure, contrast and colour in one click. What it adjusts, when to use it, and how — free.
Crop any photo into a clean circle with transparent corners for Slack, Discord, forums, and team pages. Learn the framing and PNG tips, free in your browser.
The favicon is the tiny icon in every browser tab. The sizes you need, how to make one from any image, and design tips so it reads at 16px — free.
Photos carry hidden GPS location, dates and device details — sharing one can reveal where you live. How to strip EXIF metadata before you share.
Protect your photos and credit your work with a text or logo watermark: the best placement and opacity, and how to watermark a photo free online.
Pull the original photos, charts and logos out of a PDF at full quality — far better than a screenshot. Extract-images vs page-to-image, plus tips.
Turn a PDF into web content with reflowing text, real headings and exported images, ready to publish online. What converts cleanly, and how — free.
Flattening merges form fields, signatures and annotations into the page so they can’t be edited or reset. When and how to flatten a PDF, free online.
Need a few pages from a big PDF? Extract a page range into a clean new file — and when to extract vs split vs delete pages. Free online.
Cut wasted white borders from scans and slide exports so your content fills the page. Crop vs resize, common cases, and how to crop a PDF free.
PDF/A is the archival PDF standard — self-contained and built to render for decades. Who needs it, the conformance levels, and how to convert free.
Turn a PDF slide deck back into editable PowerPoint slides. See what converts cleanly, what needs cleanup, and how to convert PDF to PPTX free in your browser.
A black box drawn over text leaves it fully recoverable. How to redact a PDF properly — permanently removing sensitive data — and what to redact.
A “file is damaged” error isn’t always the end. Learn why PDFs corrupt, what a repair tool can recover, and how to fix a broken PDF free in your browser.
Merged and scanned PDFs often lack page numbers. Add clean, sequential numbers with the right position, format and start page — free online.
Stamp CONFIDENTIAL, DRAFT or your logo across every page of a PDF: text vs image watermarks, the best opacity and angle, and how to do it free.
A scanned PDF is just images — you can’t search or copy its text. OCR adds a searchable text layer. How to OCR a PDF free online, plus accuracy tips.
A comprehensive comparison of JPEG, PNG, WebP, and AVIF image formats with real file size numbers, browser support data, and clear guidance on when to use each.
AI upscaling reconstructs real detail instead of just stretching pixels. How it works, what it’s best at, and how to get great 2× and 4× results.
AI inpainting fills the gap left by a removed object with convincing, matching content. A step-by-step guide to removing photobombers and clutter.
AI colorization predicts realistic colours for black-and-white photos in seconds. How it works, which photos colorize best, and how to prepare yours.
AI portrait enhancement sharpens and restores faces in old, blurry or low-resolution photos. A complete workflow for reviving faded family pictures.
OCR pulls text out of images, screenshots and scans so you can copy and edit it. When it works best, how to improve accuracy, and what to expect.
What makes a meme work, how to use popular templates, and how to make your own in under two minutes — free, no design skills needed.
AI screenshot-to-code tools generate functional HTML, CSS, and React code from a UI image — turning mockups and designs into working front-end code in seconds.
Pull the dominant HEX and RGB colours from any image for brand matching, website themes and design inspiration — a step-by-step guide with tips.
Why PDFs bloat, which compression level to pick, and how to shrink image-heavy PDFs by up to 80% without visible quality loss.
Convert a PDF into an editable Word document: text PDFs vs scanned PDFs, what quality to expect, and how to fix common conversion problems.
Why PDF beats .docx for sharing, how to convert Word to PDF online with fonts and layout kept, and how to fix the most common conversion issues.
Split a PDF by page range, into equal parts, or into single pages — when and why you’d split one, with step-by-step instructions.
Turn PDF pages into images for social posts, websites or editing — with a DPI guide for screen vs print, and when to pick JPG or PNG.
Combine JPG, PNG or WebP images into one PDF in minutes: setting the page order, fit or fill, and keeping the final file size manageable.
Add AES-256 encryption to a PDF in seconds. The two kinds of PDF password, how strong the protection really is, and how to share protected files.
Unlock your own password-protected PDF instantly — no software. User vs owner passwords explained, and how to manage access after unlocking.
Fix wrong page order, rotate sideways scans, and remove blank or unwanted pages from any PDF using a visual drag-and-drop interface — no Adobe Acrobat needed.
Sign a PDF in under a minute, no printing. The types of electronic signature, where each is accepted, and how to add yours online.
PDF metadata controls how a document shows in browser tabs, search results and file systems. Which fields matter, and how to edit title and author.
AI paraphrasing restructures text far beyond swapping synonyms. What paraphrasing really means, what still counts as plagiarism, and how to use it well.
AI grammar checkers catch what spell checkers miss — homophones, subject-verb agreement, dangling modifiers. A practical guide to using one well.
AI summarizers turn thousands of words into key points in seconds. Extractive vs abstractive summaries, when to trust the output, and how to use them.
Why word and character counts matter for meta tags, social posts, essays and briefs — with a reference table of platform character limits.
Every text case explained — UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case — with use cases and a one-click converter.
A text diff highlights what was added, removed and kept between two versions. When to compare by word or by line, and tips for accurate results.
Markdown is the standard for docs, READMEs and blog posts. A beginner’s guide to all the core syntax, with before-and-after examples.
Raw JSON is hard to read, and invalid JSON fails silently. How to format, validate and debug JSON, with every common error explained and fixed.
Lorem ipsum has been designers’ placeholder text for decades. Its surprising history, why it beats real text in mockups, and how to generate any amount.
How text-to-speech works, what it’s useful for, and how to turn text into natural-sounding speech with your browser’s voices — free, no account.
Turn your speech into text live from your microphone. How browser speech recognition works, how to get more accurate results, and common uses.
Emojis break database encodings, look out of place in formal documents and upset text analysis. Why, and how to strip them all in one click.
QR codes can hold URLs, contact cards, WiFi logins and more. How to make one in your brand colours, choose error correction, and print it to scan.
Weak and reused passwords cause most account breaches. What makes a password truly secure, how fast yours could be cracked, and how to make strong ones.
Base64 shows up in JWTs, email attachments, data URIs and Basic Auth. What it does, why it exists, and how to encode and decode it free in your browser.
Spaces, special characters and non-ASCII text in URLs must be percent-encoded. Why URL encoding exists, when you need it, and mistakes to avoid.
JWTs are everywhere in modern login systems but unreadable at a glance. The token structure, what each standard claim means, and how to decode one.
Regular expressions are one of the most useful skills in programming. A beginner’s guide to the core syntax, with practical examples and a live tester.
CSS gradients add depth without image files. A guide to linear, radial and conic gradients, with a syntax reference and design patterns to copy.
HEX, RGB, HSL and CMYK compared: where each colour format is used in design tools, CSS and print, and how to convert between them.
Unix timestamps are the universal time format of databases, APIs and logs. What they are, the seconds-vs-milliseconds trap, and how to convert them.
MD5 is broken, SHA-1 is deprecated, SHA-256 is today’s standard. How cryptographic hash functions work, what makes one secure, and which to choose.
HTML entities display characters like < and & as literal text — and help prevent XSS. When to encode them, which ones matter, and how to do it.
Your title tag and meta description are your ad in search results. How to write meta tags that earn clicks, plus a reference for every SEO meta tag.
Image sizes for every social network, resizing vs cropping explained, and a step-by-step guide to getting the exact pixel dimensions you need.
AI-powered background removal works in seconds and produces professional results even on complex edges like hair. Learn how to do it free in your browser.
From paraphrasing and grammar checks to instant summaries, these free AI writing tools handle the tedious parts of writing so you can focus on the ideas.
Need to combine multiple PDFs into one document? This step-by-step guide shows you how to merge PDFs instantly in your browser — no Acrobat needed.
Large images slow down your website and hurt your SEO. Learn the best formats, settings, and free tools to compress images without visible quality loss.
More guides coming soon.