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Web-safe colours
Browse all 216 web-safe colours grouped by the red channel (each channel steps 00 / 33 / 66 / 99 / CC / FF); click a swatch to select it, then copy the HEX, the 3-digit shorthand, RGB, HSL, HSV, CMYK and the contrast against black or white text. Any colour you type is snapped to the nearest safe colour, and you can filter by value or show greys only.
Free and no sign-up. Web-safe colours computes and renders entirely in your browser; nothing you enter is uploaded.
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Frequently asked questions about Web-safe colours
- What is a web-safe colour? Why are there only 216 of them?
- Web-safe colours use only 0, 51, 102, 153, 204 and 255 per channel (hex 00 / 33 / 66 / 99 / CC / FF), which gives 6 × 6 × 6 = 216 combinations. They date from the era of 8-bit colour displays: of the 256-entry palette the system permanently reserved 40, leaving browsers and web pages 216 colours that displayed without dithering.
- Do I still need web-safe colours today?
- Modern devices are almost all 24-bit true colour, so pages need no longer stay within 216 colours. In constrained settings such as e-ink screens, old projectors, embedded displays and email templates, safe colours are still steadier, and 216 colours are plenty when you need to pick quickly a set that will not shift on screen.
- How is an arbitrary colour converted to the nearest safe colour?
- Each of the R, G and B channels is rounded to the nearest of 0 / 51 / 102 / 153 / 204 / 255, which gives the closest safe colour by RGB distance, and the page shows both the colour difference and the rounded channel values. The converted colour looks different from the original (saturation or lightness is usually pulled to the nearest step), so keep the original values when a brand colour has to be reproduced exactly.
- How are the three-digit shorthand and the contrast ratios computed?
- Every channel of the 216 safe colours is a repeated pair of hex digits, so all of them can be written in #RGB shorthand: #3399CC and #39C are equivalent, for example. Contrast is computed with the WCAG relative luminance formula for white and black text on that colour: aim for at least 4.5:1 for body text and 3:1 for large text.
- Does the content these tools process stay local?
- No. Your input exists only in the memory of the current page, is released when you reload or close it, and is never written to local storage.
- Can I keep using the tools offline?
- Once the page has loaded, formatting, encoding, regex and password calculations need no network; only the IP address page needs to be online, because it asks our backend for your local outbound address when it opens.
- Do I need to register or pay to use Web-safe colours?
- Almost every tool is free, needs no registration or sign-in and has no usage limit; the few pay-per-use features (such as AI watermark removal, AI image generation, AI upscaling, AI annotation, and AI flowchart, mind-map and Mermaid generation) state their prices on the page.
- Is the data I process with Web-safe colours uploaded to a server?
- No. Calculation and rendering run locally in the browser and your input is never sent to a server; only the IP address page asks our backend for your outbound address when it opens, and that request carries none of your input. Features that need the backend (such as AI watermark removal, AI image generation, AI upscaling, AI annotation, AI flowchart and mind-map generation and "Financial statements – Small Business Accounting Standards") state their upload scope on their own pages.
About Local Toolbox
Local Toolbox gathers the small tools you reach for every day into one place: formatters, encoding converters, date maths, ID card and address parsing, image and QR code handling, password and amount conversion. Open a page and start working — no sign-up, and almost every tool has no usage limit.
Most features compute inside your browser, so your input never leaves your device; the pages are plain static assets, load fast and keep working offline. The IP page asks our backend for your outbound address when it opens and sends none of your input. AI watermark removal, AI background removal, AI image generation and AI upscaling send content to our backend for inference (watermark removal is ¥1 per run; background removal is ¥1 per run; image generation and upscaling are priced by resolution — 2K ¥2, 4K ¥3); AI annotation sends images to a large model that locates the target and returns coordinates (¥0.5 per image, refunded only when every image in the batch fails); AI flowchart, AI mind-map and AI Mermaid chart generation send your text description to a model that builds the diagram (three separate products, charged ¥0.5, ¥0.5 and ¥0.5 per run respectively); and the accounting helper sends the income, expense, social-insurance and balance figures you fill in to generate a report (¥0.5 for the spoken analysis, ¥1 for the report). These features accept Alipay only, upload nothing before payment succeeds, and refund automatically if processing fails.
- Local first: Parsing, conversion, encoding and image processing all happen in your browser and nothing you type is uploaded (AI watermark removal and AI background removal need the image, AI image generation and upscaling need one upload to obtain a URL, AI annotation needs the images for the model, AI résumé rewriting needs your résumé text, AI flowchart and mind-map generation need your text description, and the accounting helper needs the figures you submit).
- Pay per use, prices in plain sight: Almost every tool is free, needs no account and has no usage limit. Only AI watermark removal (¥1 per run), AI background removal (¥1 per run), AI image generation and AI upscaling (2K ¥2, 4K ¥3), AI annotation (¥0.5 per image), AI résumé rewriting (¥0.5 per run), AI flowchart, mind-map and Mermaid chart generation (¥0.5, ¥0.5 and ¥0.5 per run) and the accounting helper (¥0.5 for the spoken analysis, ¥1 for the report) are charged per use. Payment is Alipay only, nothing is uploaded before you pay, and failed runs are refunded automatically.
- One link per tool: Every tool has its own link, so bookmarks and shared URLs always land on the same page.
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