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Learn and practise programming in your browser. Pick a language: write code, run it in a real terminal and follow the lessons step by step.
Why Shiklo Tools?
Simple, private tools that just work — right in your browser.
- Private Everything runs in your browser. Files are never uploaded.
- Secure Encrypted HTTPS connection, and nothing you open is stored on our servers.
- No login required No account, no sign-up, no email. Just open a tool and use it.
- Fast No upload or download wait — results appear instantly.
- Free All tools are free to use, with no limits.
- Works everywhere Phone, tablet or computer, in any modern browser.
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Frequently asked questions
Are my files or text uploaded anywhere?
No. Every tool runs inside your browser on your own device. Nothing you enter or open is sent to a server.
Do I need to create an account or log in?
No login is required. There are no accounts — open any tool and start using it straight away.
Are the tools really free?
Yes. All tools are free, with no limits or watermarks. The site is supported by ads.
Does it work on my phone?
Yes. The tools work in any modern browser on phones, tablets and computers.
Can I use the tools offline?
Once a tool has loaded it does its work on your device, so it keeps working even if your connection drops.
Which file types are supported?
PDF, Word, Excel, PowerPoint, OpenDocument and RTF documents, JPG, PNG, WebP, HEIC, AVIF, GIF and BMP images, MP4, MOV, WebM and MKV videos, MP3, WAV, M4A, OGG and FLAC audio, ZIP, 7z, RAR, TAR and GZIP archives, CSV, JSON, XML and plain text. Each tool lists exactly what it opens.
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File Size Analyzer
See a file's exact size in bytes, KB and KiB, size on disk, upload time, real type, entropy and SHA-256.
Drop any file to see exactly how big it is and what is inside it. The analyzer shows the size in bytes and in both kinds of units, decimal (KB, MB, GB, as storage makers and macOS use) and binary (KiB, MiB, GiB, as Windows uses, even though it labels them KB and MB), the space the file takes on disk, and how long it takes to upload or download at common connection speeds.
It also looks at the content: the real file type from its signature, whether the extension matches, the entropy of the bytes (which tells you whether the file is already compressed or encrypted), how much ZIP-style compression would save, and its SHA-256 checksum. Text files get line, word and character counts, the encoding and the line-ending style; images get their pixel size and the memory they need when opened. The file is read in chunks in your browser, so files of several gigabytes work, and nothing is uploaded.
How to use File Size Analyzer
- Choose or drop a file of any type and size.
- Read the size tiles: exact size, type, entropy and possible compression savings.
- See the details table, the SHA-256 checksum and the size in every unit.
- Check the upload and download times for your connection.
Features
- Exact size in bytes, KB, MB, GB and KiB, MiB, GiB
- Size on disk and upload / download times
- Real file type and extension check
- Entropy and compression estimate
- SHA-256 checksum, text counts, image dimensions
- Any size, read in chunks on your device
KB or KiB? Why sizes differ between systems
A kilobyte (KB) is 1,000 bytes in the international (SI) system that disk makers, macOS and most phones use. A kibibyte (KiB) is 1,024 bytes, and Windows Explorer shows sizes in these binary units while still writing KB, MB and GB. That is why a 1 TB drive appears as about 931 GB in Windows: nothing is missing, the unit is different. The gap grows with each step, about 2.4% for KB, 4.9% for MB and 7.4% for GB.
| Exact size | Decimal | Binary (Windows) |
|---|---|---|
| 1,000,000 bytes | 1 MB | 0.95 MiB |
| 5,242,880 bytes | 5.24 MB | 5 MiB |
| 104,857,600 bytes | 105 MB | 100 MiB |
| 1,000,000,000,000 bytes | 1000 GB | 931 GiB |
How long will an upload take?
Connection speeds are quoted in megabits per second, and a byte has 8 bits, so a 100 Mbit/s connection moves at most 12.5 megabytes a second. The tool divides the file size by the speed; real transfers are a little slower because of protocol overhead and other traffic, and upload speeds are often much lower than download speeds on home connections. For a 100 MB file (100,000,000 bytes):
| Connection | Time for 100 MB |
|---|---|
| 10 Mbit/s | 1 minute 20 seconds |
| 100 Mbit/s | 8 seconds |
| 1 Gbit/s | 0.8 seconds |
Size on disk
File systems store files in fixed blocks called clusters, 4 KiB (4,096 bytes) by default on Windows NTFS, macOS APFS and Linux ext4. A file always occupies whole clusters, so a 1-byte file takes 4,096 bytes on disk and a 5,000-byte file takes 8,192. This is why a folder of many small files uses far more disk space than the sum of their sizes. Very small files can be stored inside the file table on NTFS, and compressed or sparse files may use less; the tool shows the usual case.
What entropy tells you
Entropy measures how unpredictable the bytes are, from 0 bits per byte (the same byte repeated) to 8 (completely random). Plain text and source code are usually between 4 and 5, because they use a limited set of characters. Programs and uncompressed images fall in the middle. Anything close to 8 is already compressed or encrypted: ZIP and RAR archives, JPEG photos, MP3 and MP4 files, and encrypted containers. Compressing such files again saves almost nothing, which the compression estimate confirms. An unexpectedly high entropy in a file that should be text or a document can also be a sign that it has been encrypted, for example by ransomware.
The SHA-256 checksum
The checksum is a 64-character fingerprint of the exact bytes. Any change, even one bit, produces a completely different value, so you can compare it with the checksum published on a download page to confirm the file is complete and unmodified, or compare two files without opening them. For several hash types at once, or to compare against an expected value, use the Hash Generator.
Frequently asked questions
How do I check a file's exact size in bytes?
Drop it here. The first tile and the details table show the exact number of bytes, plus every common unit.
Why does Windows show a different size?
Windows divides by 1,024 and calls the result KB, MB and GB; storage makers and macOS divide by 1,000. Both are shown here.
What is size on disk?
The space the file really occupies: whole 4 KiB clusters, so small files take more room than their size.
Is there a file size limit?
No fixed limit. The file is read in 4 MB chunks, so even files of several gigabytes can be analysed; text counts are shown for text files up to 50 MB.
What does high entropy mean?
Close to 8 bits per byte means the data is compressed or encrypted, so zipping it will not make it smaller.
Is my file uploaded?
No. It is read in your browser and never leaves your device.
Related tools
File Type DetectorFind out what a file really is from its content (magic bytes), not its name, and see if the extension is wrong.
Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE3 and CRC32 hashes of text or files of any size, with HMAC and checksum comparison. Private.
Duplicate File FinderFind identical files in a folder or a set of files by their content (SHA-256), with the space wasted and a CSV report.
ZIP CreatorCreate a ZIP file from files and whole folders in your browser, keeping the folder structure, with normal, maximum or no compression.
Image CompressorCompress JPG, PNG and WebP images in your browser — up to 80% smaller with no visible loss. Batch, target size (e.g. under 100 KB), no upload.