40free tools
6categories
0accounts or uploads
100%client-side
Small tools, properly made.
Tools Blis is a workbench of forty single-purpose online tools — generators, converters, " "checkers, calculators and counters. Every one of them runs entirely in your browser, so nothing " "you type, paste or open ever leaves your device.
Security
Passwords, hashes and IDs — lock things down properly.
SecurityPassword GeneratorRandom passwords with a live entropy score.
SecurityPassphrase GeneratorMemorable multi-word passphrases, truly random.
SecurityPassword Strength CheckerHonest entropy, crack-time and pattern warnings.
SecurityHash GeneratorFive cryptographic hashes, computed live.
SecurityUUID GeneratorRandom v4 UUIDs, one or fifty at a time.
Images
Compress, resize, convert and favicon-ify without uploads.
ImagesImage CompressorShrink photos in your browser, nothing uploaded.
ImagesImage ResizerExact pixel dimensions, right in the browser.
ImagesImage ConverterPNG, JPEG and WebP — genuinely re-encoded, right here.
ImagesFavicon GeneratorA proper favicon set — from any image or a single letter.
ImagesImage Colour PickerPoint at any pixel — get its exact colour, instantly.
Colour
Pickers, palettes, gradients and contrast ratios.
ColourPalette GeneratorFive colours that belong together — from one base.
ColourGradient GeneratorBeautiful CSS gradients, built visually, copied in one click.
ColourContrast CheckerPass or fail, by the numbers — no squinting required.
ColourColour StudioOne colour, four languages — plus its whole family.
Data
JSON, Base64 and URL encoding — developer staples.
DataJSON FormatterTidy up messy JSON with validation and one-click minify.
DataJSON to CSV ConverterConvert JSON to CSV and back — spreadsheet-ready in seconds.
DataBase64 Encoder & DecoderEncode and decode Base64 — and no, it is not encryption.
DataURL Encoder & DecoderPercent-encode URLs properly: full URL, component, or decode.
DataRegex TesterTest regular expressions live, with match highlighting.
DataUnix Timestamp ConverterTimestamps to dates and back — UTC, local and ISO.
DataMeta Tag GeneratorSEO and social meta tags from one simple form.
DataCSV to JSONTurn CSV spreadsheets into clean JSON.
DataJWT DecoderRead the header and payload inside any JWT.
Text
Count, convert, compare and generate placeholder text.
TextDiff CheckerSpot every change between two versions of a text.
TextWord CounterLive word, character and reading-time counts.
TextCase ConverterThirteen text-case formats in one click.
TextLorem Ipsum GeneratorPlaceholder text by paragraph, sentence or word.
TextMarkdown PreviewerWrite Markdown, see formatted output live.
TextText to SpeechHear any text read aloud in your browser.
TextTyping Speed TestMeasure your typing speed and accuracy live.
TextWord Frequency CounterMost-used words, density and keyword stats.
TextMorse Code TranslatorText to Morse and back, with sound playback.
Calculators
Everyday maths: BMI, age, units and percentages.
CalculatorsBMI CalculatorYour BMI, category and healthy weight range — instantly.
CalculatorsAge CalculatorExact age in years, months and days — plus totals.
CalculatorsUnit ConverterLength, weight and temperature — converted live.
CalculatorsPercentage CalculatorDiscounts, shares and change — three calculators in one.
CalculatorsStopwatch & TimerPrecision stopwatch with laps — plus countdown alarm.
CalculatorsRandom Number GeneratorFair numbers, dice and coin flips — truly random.
CalculatorsEMI CalculatorMonthly EMI, total interest and yearly payoff schedule.
CalculatorsCompound Interest CalculatorWatch savings grow with compounding, year by year.
Why another tools site?
Because most of them treat the tool as bait. The real product is usually the sign-up form, the file you upload, or the data trail you leave behind. Tools Blis is built the other way round: the tool is the product. You arrive, you do the job, you leave — and since every calculation happens inside your browser, there is no server quietly keeping a copy of what you made.
Built like a tool, not a funnel
Each page follows one template: the working tool at the top, then a plain-language explanation of what it does, its honest limits, and answers to the questions people actually ask. No countdown timers, no fake download buttons, no maze of ads between you and the result. If a tool cannot do something, the page says so.
Latest articles
ArticleCompound Interest: The Eighth Wonder, Explained HonestlyCompound interest explained honestly: how compounding works, frequency effects, the Rule of 72, and inflation's counterweight. General education only.
ArticleCSV vs JSON: Two Ways the World Moves DataCSV vs JSON explained: flat rows versus nested structures, when each format wins, quoting pitfalls, and real-world examples.
ArticleWord Frequency: What Counting Words Reveals About WritingWord frequency analysis for writers: crutch words, lexical density, keyword stuffing, and practical editing uses.
ArticleMorse Code: From Telegraph Wires to Your BrowserMorse code history and how it works: dots, dashes, timing rules, prosigns, and surprising modern uses.
ArticleJWTs Demystified: What's Inside That Long TokenJWT explained: header, payload, signature, base64url encoding, claims, and why you must never put secrets in the payload.
Frequently asked questions
Are the tools really free?
Yes. Every tool on this site is free, with no account, no quota and no watermark on anything you download or copy.
Is anything I type or open uploaded?
No. All processing happens in your browser with JavaScript. There is no upload endpoint for the tools to send your data to — you can verify it by loading a tool, disconnecting from the internet, and watching it keep working.
Do the tools work offline?
Once a page has loaded, yes. The calculations are local, so a dropped connection does not stop the work.
Why does every tool live on its own page?
So each page can explain its tool properly and load fast, and so you can bookmark exactly the tool you use every week.
Can I suggest a new tool?
Yes — the contact page is the place. The collection grows by request, and gaps are listed honestly rather than filled with half-finished tools.