A Collection of Free and Useful Online Tools: Text Processing, Image Editing, AI Writing, Format Conversion, Ready to Use

In the work and study scenarios of 2026, we are increasingly less likely to download software that takes up hundreds of megabytes for a small need. If you need to merge a PDF, remove a background from an image, polish a piece of Chinese into business English, convert Markdown to Word, or use AI to come up with a WeChat official account title—if you had to install software for all these tasks, your computer would soon become a dumping ground. As a result, online tool collections that are "ready to use in the browser" have become the new efficiency infrastructure: no installation, no updates, cross-device, no local resource consumption, and most are free.

This article focuses on four high-frequency scenarios: text processing, image editing, AI writing, and format conversion. It sorts out a truly practical matrix of free online tools and discusses the trade-offs behind "ready to use."

1. Why "Online Tool Collections" Are Replacing Lightweight Software

In the past, we distinguished between "professional software" and "small tools." Professional tasks were left to Photoshop, Office, Premiere; small tasks we endured and did manually. But the middle ground is the largest: you don't want to buy Acrobat for a PDF splitting feature you use six times a year, nor do you want to open PS just to remove the background from a product image occasionally.

The rise of online tools solves three problems:

• Zero deployment cost: They work in school computer labs, company visitor machines, internet cafes, tablets, and mobile browsers, without relying on the local environment.

• Task-based interaction: Upload/paste → process → download, three steps, no mental burden of "new project/save project/export settings."

• The free tier is sufficient for daily use: PDF24, Photopea, Squoosh, DeepL Basic, Remove.bg low-resolution version, TinyWow, etc., cover 80% of non-professional needs.

Of course, there are trade-offs: don't upload sensitive files carelessly, large files are limited by network speed, and complex engineering capabilities are weaker than desktop versions. We'll discuss how to leverage strengths and avoid weaknesses later.

1. Text Processing: From "Being Able to Write" to "Writing Correctly and Quickly"

Online text tools are divided into three layers.

The first layer is basic editing and formatting. For temporary inspiration, use web notepads like Online Notepad; for writing Markdown, use StackEdit or Dillinger, with writing on the left and preview on the right, and export to HTML/PDF; for word count, character count, and reading time, use Word Counter; for case conversion, camelCase to underscore, and batch numbering, use Wawa Tools or Toolfk's text batch processing, which is faster than Excel formulas.

The second layer is proofreading and polishing. For English, Grammarly web version and Hemingway Editor can highlight passive voice and long complex sentences when you paste a paragraph; for Chinese, Mita Writing Cat and Volcano Writing handle sensitive words, grammatical errors, and punctuation normalization; DeepL Write and DeepL Translate handle cross-language polishing, making it more like a "native speaker's revision" than general translation.

The third layer is structured document collaboration. WPS Online, Tencent Docs, Shimo Docs, Feishu Docs, and Word Web Version can already handle most of the "create document—multi-person edit—export PDF" loop, and you can log in directly with WeChat/QQ/enterprise accounts without building a separate system.

Practical example: On Friday night, I received client feedback in Word. I opened it in Word Web Version, turned on track changes, made edits, pasted it into Mita Writing Cat to check for grammatical errors, then ran it through Grammarly to check the English summary. I never opened desktop Office.

1. Image Editing: "Lightweight PS" in the Browser

Image editing is the most competitive track for online tools because CV models and WASM performance are sufficient.

• All-in-one editor: Photopea is a browser-based Photoshop with layers, masks, pen tool, PSD import, and consistent shortcuts, making emergency edits zero-learning-cost.

• AI cutout and restoration: Remove.bg removes backgrounds with one click; Tencent ARC restores old photos with face enhancement; waifu2x upscales and denoises anime images; UUPOOP (GaiTuBao) turns common PS actions into web buttons, such as changing ID photo backgrounds and batch watermarks.
• Compression and format: Squoosh (by Google) supports WebP/AVIF, drag and drop and slide to see file size; TinyPNG batch compresses JPG/PNG; docsmall also compresses GIF and PDF.

• Design templates: Canva, Gaoding Design, Meitu Web Version—non-designers can make posters/WeChat official account covers/e-commerce main images by selecting templates and changing text in 10 minutes.

Note a red line: For ID cards, contract scans, and unpublished product images, try to use sites that declare "client-side processing" like FastDo and ToolFlow, and don't upload to ordinary cloud tools. FastDo runs 200+ tools locally, files never leave the device; ToolFlow uses pdf-lib + WASM for PDF/image processing in the browser, privacy-friendly.

1. AI Writing: Not Ghostwriting, but a "Draft Accelerator"

In 2026, saying "AI writing tools" is no longer surprising; the key is to use them by category:

• General assistants: Doubao, Kimi, ChatGPT free tier, Claude free tier, responsible for outlining, writing weekly reports, summarizing long articles, and generating video scripts. Kimi excels at long document parsing, Doubao is grounded in Chinese contexts, suitable for students and operators.

• Specialized writing: Mita Writing Cat fixes grammatical errors, QuillBot does synonym rewriting, DeepL Write does cross-language polishing, Rytr writes e-commerce descriptions and Xiaohongshu copy. They are not as smart as large models, but they are more stable for single tasks and don't make things up.

• Integrated in tool sites: TinyWow, ToolFlow, MikuTools turn "AI write copy/summarize/rewrite" into buttons, combined with the previous PDF/image functions, forming a pipeline of "upload file → AI extract key points → polish → export."

Usage discipline is important: AI produces the first draft, humans do fact-checking and tone control. Especially for contracts, papers, and press releases, models may fabricate numbers that look plausible but are actually wrong.

1. Format Conversion: The "Bread and Butter" of Online Tools

This area is the most mature and the most convincing for "ready to use."

• Document conversion: PDF24 Tools is completely free and watermark-free, with PDF to Word/image, merge, split, compress, and unlock password all in one; ILovePDF and Smallpdf are sufficient for occasional use (with daily limits); CloudConvert supports 200+ formats, PDF↔Office, video to GIF, HTML→PDF, with about 25 free conversions per day; Convertio can pull files from cloud storage.
• Audio and video: Online Audio Converter changes formats; VocalRemover separates vocals; CapCut Web Version and Kapwing do rough cuts of short videos with subtitles.

• Developer-oriented: JSON formatting, Base64, regex testing with Regex101, ToolCool, 10015tools; DiffChecker compares contract/code version differences, ten times more reliable than manual eye scanning.

The selection principle is simple: for occasional use, choose CloudConvert/PDF24; for frequent sensitive PDF handling, choose local-type FastDo/ToolFlow; for batch tasks, go back to desktop HandBrake/ExifTool, don't fight with browser memory.

1. Several "Aggregator" Sites Worth Bookmarking Separately

Instead of bookmarking twenty single-function sites, save three to five aggregator sites:

1. PDF24 Tools (pdf24.org) — The conscience of the PDF world, free and ad-free.
2. TinyWow / MikuTools — 200+ functions, PDF, images, AI writing, video compression all together, English interface but intuitive.
3. FastDo (fastdo.tools) — No registration, no upload, local processing, privacy-first.
4. ToolFlow AI (toolflowai.app) — 78+ tools, AI writing + PDF + images + video, claims in-browser processing.
5. Wawa Tools / Calvin Toolbox — Chinese essential needs, such as uppercase amounts, timestamps, QR codes, and relative relationship calculator.