How do I split a large file online?

Add your file, choose how to split it (by size, number of parts, platform limit, smart mode or PDF pages), then click Split. Download the parts individually or as a ZIP. To rebuild the original later, open the Join tab and drop all the parts back in.

How do I split a file into smaller parts?

Drop the file in, pick “By size” and a chunk size (for example 10 MB), and the tool slices the file into sequential parts named file.ext.001, file.ext.002 and so on. A live preview shows how many parts you will get before you commit.

What does splitting a file actually do?

Splitting reads your file and copies consecutive byte ranges into separate smaller files. The parts together contain exactly the same bytes as the original, in order, so concatenating them rebuilds the file perfectly — no data is changed, compressed or lost.

Is this file splitter free?

Yes. Splitting and joining files is completely free — no sign-up, no watermark, no daily limit and no file-size cap beyond your device’s memory. A developer API is available for automated, server-side and high-volume use.

Do I need to install any software?

No. The splitter runs in your web browser, so there is nothing to download or install. It works on Windows, macOS, Linux and ChromeOS, and on mobile, in any modern browser.

What file types can I split?

Any file type — videos, ISO images, archives (ZIP, RAR, 7z), virtual-machine disks, databases, backups, PSD/AI design files, audio, documents, datasets and raw binaries. Splitting is byte-level, so the file format does not matter.

Is there a file-size limit?

There is no fixed cap. Because the tool slices files lazily with the browser’s Blob API (it never loads the whole file into memory at once), very large files — tens of gigabytes — can be split on a capable desktop. The practical limit is your device’s available memory and disk.

Can it split files larger than 50 GB?

Yes, on a desktop with enough disk space. The splitter uses lazy slicing so it does not read the entire file into RAM; it streams each chunk to a download as it is created. Whole-file SHA hashing is skipped above 256 MB (MD5 still streams) to keep huge files fast.

Are my files uploaded to a server?

No. Everything happens in your browser — the file is read, sliced, hashed, optionally encrypted and downloaded entirely on your device. Nothing is transmitted, so it is private and GDPR-friendly by design.

What ways can I split a file?

Five modes: By size (fixed chunk size), By parts (an equal number of pieces), By platform (auto-fit Gmail, WhatsApp, Discord, Telegram and more), Smart (the tool picks an ideal size), and PDF by pages (split a PDF into page-group documents).

How do I split a file by size?

Choose “By size” and pick a chunk size — 1 MB, 5 MB, 10 MB, 25 MB, 50 MB, 100 MB, 500 MB, 1 GB or 2 GB — or type your own. Every part will be exactly that size except the last, which holds the remainder.

How do I split a file into a fixed number of parts?

Choose “By parts” and enter how many pieces you want (e.g. 5). The tool divides the total size evenly so you get that many roughly equal parts. Handy when you need to share work across a set number of recipients or disks.

What is Smart split mode?

Smart mode looks at the total file size and picks a sensible chunk size — aiming for around ten parts and snapping to a round size (e.g. 25 MB, 100 MB) — so you get a manageable number of pieces without having to do the maths.

How do I split a file to fit an email limit?

Choose “By platform” and pick your service — Gmail (25 MB), Outlook (20 MB), WhatsApp (16 MB), Discord (8 MB) and more. Each part is sized to fit that limit, so you can attach them across several messages and rejoin on the other end.

Which platforms can it auto-fit?

Built-in limits include Gmail (25 MB), Outlook (20 MB), WhatsApp (16 MB), Discord free (8 MB) and Nitro (100 MB), Telegram (2 GB), Slack (1 GB), Google Drive (5 GB), Dropbox (2 GB) and OneDrive (250 MB). Pick one and parts are sized to fit.

Can I set a custom chunk size?

Yes. In “By size” mode you can type any chunk size in addition to the presets, and in “By parts” mode you can enter any number of parts. The live preview updates to show how many pieces you will get.

How does the last chunk work?

The final part holds whatever bytes remain after the full-size chunks, so it is usually smaller than the others. With “Optimise last chunk” on, this is handled automatically — the total of all parts always equals the original size exactly.

Will all parts be the same size?

In “By size” mode every part is the chosen size except the last (the remainder). In “By parts” mode the pieces are as even as possible. The combined bytes always reconstruct the original file precisely.

How many parts will my file be split into?

The live preview tells you before you split: it divides the file size by the chunk size (or shows your chosen part count). For example a 1 GB file at 100 MB per part makes 10 parts; at 25 MB it makes 40.

How are the split parts named?

Parts are named after the original with a zero-padded sequence suffix — for example movie.mp4.001, movie.mp4.002, movie.mp4.003. This is the widely-used convention that command-line tools (cat/copy) and other splitters understand.

Why are parts numbered .001, .002 …?

Zero-padded numeric suffixes keep the parts in the correct order alphabetically and are the de-facto standard for split files. The padding width adjusts to the number of parts so 1000+ pieces still sort correctly.

Can other tools open the parts?

Yes. The .001/.002 naming and plain byte-concatenation mean you can rejoin the parts with this tool, with command-line tools, or with utilities like HJSplit and 7-Zip — any tool that concatenates sequential parts.

Do the parts change my file format?

No. Parts are raw byte ranges of the original; individually they are not playable or openable (a video part is not a valid video on its own). Once rejoined, the file is byte-identical to the original and opens normally.

Can I open a single part on its own?

Generally no — a part is a fragment of the original, not a standalone file. The exception is PDF-by-pages mode, which produces complete, openable PDFs. For all other modes you must rejoin the parts first.

How do I join split files back together?

Open the Join tab, drag in all the parts (and the .manifest.json if you have it), enter the password if they were encrypted, then click Join & verify. The original file is reassembled, integrity-checked and offered for download.

How do I reassemble split files?

Use the Join tab here — drop all the .001, .002 … parts and press Join. The tool detects the sequence, checks for missing pieces, concatenates the bytes in order, decrypts if needed and verifies the result against the manifest.

Does the joiner detect the correct order?

Yes. It reads the numeric index from each part’s name (.001, .part1, .z01, -1of5, name-1.bin and similar patterns) and sorts the parts into the right sequence automatically before joining.

What if a part is missing?

The joiner detects gaps in the sequence and tells you exactly which index is missing (e.g. “Missing parts: 3”). Because the file is incomplete, the result would be corrupt — add the missing part and join again.

Do I need the manifest file to join?

No, but it is recommended. Without it the parts are still joined by their numbered order; with the .manifest.json the tool can verify the rebuilt file’s MD5 against the original, confirming the join is byte-perfect.

How does it verify the joined file is correct?

If you include the manifest, the joiner recomputes the MD5 of the reassembled file and compares it with the original MD5 stored in the manifest. A match means the file is identical to the original; a mismatch flags corruption or a missing/wrong part.

Can I join files split by another tool?

Often yes. If another splitter used standard sequential naming (.001/.002, .partN, .zNN, -NofM), the joiner detects the order and concatenates them. Without our manifest it can’t verify the hash, but the rebuilt file is still correct if all parts are present.

How do I rejoin files on the command line?

On macOS/Linux: cat "file.ext".* > "file.ext". On Windows (cmd): copy /b part1+part2+... "file.ext". The tool generates a ready-to-paste REASSEMBLE.txt with these exact commands for your file (unencrypted parts only).

Can I join encrypted parts on the command line?

No. Encrypted parts (.enc) are AES-256-GCM encrypted and must be decrypted with the correct password — use the Join tab here, which decrypts and reassembles in one step. Plain concatenation would only give you ciphertext.

Will the rejoined file be identical to the original?

Yes — bit for bit. Splitting copies exact byte ranges and joining concatenates them in order, so the reassembled file matches the original perfectly, which the MD5 verification confirms.

What are the integrity hashes for?

A hash (checksum) is a fingerprint of the file’s contents. The tool computes hashes of the original and of every chunk so you can verify, after transfer, that nothing was corrupted — the rejoined file’s hash must match the original.

Which hash algorithms are supported?

MD5, SHA-1, SHA-256 and SHA-512. MD5 and SHA-256 are on by default. MD5 streams for files of any size; SHA hashes are computed for whole files up to 256 MB (every chunk always gets a SHA-256 fingerprint regardless of file size).

What is the difference between MD5 and SHA-256?

Both are checksums. MD5 is fast and fine for detecting accidental corruption during transfer. SHA-256 is cryptographically stronger and preferred when you need tamper-evidence. The tool can compute both; the joiner verifies with MD5 by default.

Why is SHA only computed for files up to 256 MB?

Whole-file SHA hashing requires reading the entire file, which is slow for very large files. MD5 is computed incrementally (streamed) at any size for verification, while SHA is reserved for files under 256 MB. Every chunk still gets its own SHA-256.

Does each chunk have its own checksum?

Yes. Every part gets a SHA-256 fingerprint, listed in the manifest and the .sha256 file. You can verify any single part independently — useful for confirming a re-downloaded part is intact without rebuilding the whole file.

How do I verify a part with sha256sum?

Download the .sha256 file and run sha256sum -c file.sha256 (Linux), shasum -a 256 -c file.sha256 (macOS) or CertUtil -hashfile part SHA256 (Windows) and compare. The .sha256 lists every part’s expected hash.

What is a checksum file?

A checksum file (here a .sha256) lists the expected hash of each part next to its filename. Verification tools read it, recompute each part’s hash and report any mismatch — proving the parts arrived intact.

Can hashing detect a corrupted transfer?

Yes. If any byte changes during upload, download or copy, the recomputed hash won’t match the stored one. The joiner’s MD5 check catches this automatically, and per-chunk SHA-256 lets you pinpoint exactly which part went bad.

MD5 is not collision-resistant for security purposes, but it is perfectly adequate for its job here — detecting accidental corruption during transfer. For tamper-evidence, also enable SHA-256, which is cryptographically strong.

Where are the hashes stored?

In the manifest (.manifest.json) and the human-readable instructions and .sha256 files. The original-file hashes and each chunk’s SHA-256 are recorded so anyone with the parts and manifest can fully verify the reassembly.

Can I encrypt the split parts?

Yes. Turn on AES-256 encryption and set a password; each chunk is encrypted with AES-256-GCM before download and named with a .enc suffix. Without the password the parts are unreadable. Rejoin (and decrypt) in the Join tab.

What encryption does it use?

AES-256 in GCM mode (authenticated encryption). The key is derived from your password with PBKDF2 (150,000 iterations). Each chunk stores its own random salt and IV, so the encryption is strong and each part is independently authenticated.

Is the encryption secure?

Yes. AES-256-GCM is a modern, authenticated cipher used across the industry, and PBKDF2 with 150,000 iterations slows brute-force attacks on your password. The strength ultimately depends on choosing a strong, unique password.

What happens if I forget the encryption password?

The parts cannot be recovered. Encryption is done locally with no backdoor and no password stored anywhere, so a forgotten password means the data is unrecoverable. Use the built-in generator and save the password somewhere safe.

Can the tool generate a strong password?

Yes. Click Generate to create a strong random 20-character password, and the strength meter rates any password you type. A long, mixed-character password gives the best protection.

How do I decrypt and rejoin encrypted parts?

In the Join tab, drop the .enc parts, type the password in the password field, and click Join & verify. Each part is decrypted with AES-256-GCM and the original file is reassembled — all on your device.

File Splitter Free Online – Split & Join Large Files into Parts

Why this is the best free file splitter

5 ways to split

By size, by number of parts, by platform limit (Gmail, WhatsApp, Discord…), Smart auto-sizing, or PDF-by-pages — with a live part-count preview.

100% private

Files are sliced, hashed and encrypted in your browser with the Blob API. Nothing is uploaded — even multi-gigabyte files stay on your device.

Integrity built in

MD5, SHA-1, SHA-256 & SHA-512 hashes for the file and every chunk, plus a manifest so the rejoin is verified bit-for-bit.

AES-256 encryption

Optionally encrypt each chunk with AES-256-GCM (PBKDF2, 150k iterations). Unreadable without your password; tamper-detected on decrypt.

Verified joiner

Drop the parts back in — the joiner detects the sequence, flags missing pieces, decrypts and verifies the MD5 automatically.

Real downloads & reports

Individual parts, an all-in-one ZIP, JSON manifest, CSV report, reassembly instructions and a .sha256 checksum file.

What is a file splitter?

A file splitter divides one large file into several smaller pieces — parts, chunks or volumes — so it’s easier to send, upload or store, and then reassembles those pieces back into the exact original. It solves a practical problem: many channels (email, chat apps, basic cloud storage, FAT32 drives) cap how big a single file can be, and big files are slow and fragile to transfer in one shot.

Splitting is byte-level, so it works on any file type — videos, disk images, archives, VM disks, backups, datasets or raw binaries. This tool slices and rejoins files entirely in your browser using the Blob API (lazy, so huge files don’t exhaust memory), computes integrity hashes, can encrypt each chunk with AES-256, and writes a manifest so the rejoined file is verified bit-for-bit. Nothing is ever uploaded.

Why split a file?

Splitting unlocks transfers and storage that a single large file can’t do. The most common reasons:

Beat size limits — fit Gmail, WhatsApp, Discord, Telegram and other per-file caps.
Transfer reliably — if one part fails, re-send just that part, not the whole file.
Store on small media — spread parts across USB sticks, DVDs or FAT32 drives.
Share privately — split (and encrypt) locally instead of uploading to a cloud splitter.
Parallelise — upload or download parts at the same time to go faster.
Archive & back up — break huge backups into verifiable, manageable pieces.

Split a file in 4 steps

Add your file

Drag in any file (or browse / drop a folder). It is analysed instantly — type, size, integrity hashes, recommended chunk sizes and which platforms it already fits — entirely in your browser. Huge files are handled lazily, so even multi-gigabyte files load instantly.

Choose how to split

Split by fixed size (10 MB, 100 MB, 1 GB…), by number of parts, by platform limit (Gmail, WhatsApp, Discord, Telegram…), let Smart mode pick an ideal chunk size, or split a PDF into page groups. A live preview shows exactly how many parts you will get.

Add integrity & security

Pick hash algorithms (MD5, SHA-1, SHA-256, SHA-512) so every part can be verified, and optionally turn on AES-256 encryption with a password so the parts are unreadable without it. A manifest is generated automatically.

Split & download

Click Split. Download parts individually, grab them all as a ZIP, or save the manifest, CSV report, reassembly instructions and .sha256 checksums. Rejoin any time in the Join tab — integrity is verified automatically.

Whole file vs split parts

Keeping a file whole is simplest when it fits your channel; splitting wins the moment size, reliability, storage or privacy gets in the way. The table compares the two where it matters.

Scenario	Whole file	Split parts
Fits size limits (email/chat)	Often too big to send	Sized to fit any limit
Transfer reliability	One failure restarts everything	Re-send only the failed part
Storage on small media	May exceed FAT32 / disk limits	Spread across disks, under limits
Privacy	Cloud splitters upload it	Split locally — never uploaded
Integrity	No built-in verification	Per-chunk SHA-256 + MD5 verify
Security	Plain bytes	Optional AES-256 per chunk
Reassembly	N/A	Verified one-click join

What you can split

Splitting is byte-level, so it works on any file — these are the types people split most.

Large Videos

Disk Images (ISO)

Archives (ZIP/RAR/7z)

VM Disks (VMDK/VDI)

Database Backups

Installers & Games

Design Files (PSD/AI)

Datasets & Logs

PDF Documents

Any Binary File

Best file splitter settings

Different goals call for different settings. These give the cleanest result on the first try.

Email a large file

Platform mode → Gmail/Outlook · MD5 + SHA-256 · download as ZIP

Share on Discord / chat

Platform mode → Discord 8 MB (or Nitro 100 MB) · individual parts

Confidential transfer

Size mode · AES-256 encryption · strong generated password · SHA-256

Store on a FAT32 drive

Size mode → 2 GB chunks (under the 4 GB limit) · keep the manifest

Resilient cloud upload

Size mode → 100 MB chunks · per-chunk SHA-256 · re-send failed parts

Split a PDF report

PDF by pages → 10 pages each · standalone PDFs (no rejoin needed)

Integrity, encryption & verified rejoining

Every split records fingerprints of the file and each chunk. Choose MD5, SHA-1, SHA-256 or SHA-512; MD5 streams at any size while SHA covers whole files up to 256 MB, and every chunk always carries a SHA-256 hash. When you rejoin, the tool recomputes the MD5 and compares it with the manifest, so a verified join means the file is byte-identical to the original.

For confidential data, turn on AES-256-GCM encryption with a password (PBKDF2, 150,000 iterations). Each chunk gets its own salt and IV and is independently authenticated, so the parts are unreadable without the password and tampering is detected automatically. The built-in joiner decrypts and reassembles in one step — all on your device.

Privacy, security & data handling

Your files stay yours. Splitting, hashing and encryption all run in your browser — the file is read, sliced, optionally encrypted and downloaded on your device, with nothing uploaded or logged. Because there is no server, there is nothing to store and nothing to leak; the file and its parts are released the moment you close the tab.

This makes the tool suitable for confidential, legal and personal files by design, and GDPR-friendly out of the box. For automated, server-side splitting at scale, the developer API offers the same logic with batch jobs, webhooks, format-aware chunking and team controls.

File Splitter API & large-file pipelines

Automate everything with the File Splitter API: server-side splitting and joining, byte- and format-aware chunking (lines/records), integrity hashing, AES encryption, resumable/chunked uploads, batch and asynchronous jobs, webhooks, API keys and usage analytics — the same engine as the web tool, built for scale.

Pricing runs from a Free tier for prototyping to Pro, Business and Enterprise plans that add higher volume, scheduled splitting and backups, storage connectors, data-validation rules and SLA-backed support — while the in-browser tool stays free and unlimited.

Free

$0/mo

100 split/join jobs / mo
Byte & PDF splitting
Integrity hashes
Community support

Start free

Popular

Pro

$19/mo

10,000 jobs / mo
AES encryption + manifests
Resumable chunked uploads
Webhooks & async jobs

Go Pro

Business

$69/mo

100,000 jobs / mo
Format-aware chunking
Storage connectors
Team accounts & API keys

Choose Business

Enterprise

Custom

Unlimited volume & SLA
Scheduled splitting & backups
Data-validation rules
Dedicated support

Contact sales

Frequently Asked Questions

A file splitter divides one large file into several smaller pieces (called parts, chunks or segments) so it is easier to transfer, email, upload or store. Later you reassemble (join) the parts back into the exact original file. This tool splits and joins files entirely in your browser — nothing is uploaded.

Troubleshooting guide

Why this is the best free file splitter

5 ways to split

By size, by number of parts, by platform limit (Gmail, WhatsApp, Discord…), Smart auto-sizing, or PDF-by-pages — with a live part-count preview.

100% private

Files are sliced, hashed and encrypted in your browser with the Blob API. Nothing is uploaded — even multi-gigabyte files stay on your device.

Integrity built in

MD5, SHA-1, SHA-256 & SHA-512 hashes for the file and every chunk, plus a manifest so the rejoin is verified bit-for-bit.

AES-256 encryption

Optionally encrypt each chunk with AES-256-GCM (PBKDF2, 150k iterations). Unreadable without your password; tamper-detected on decrypt.

Verified joiner

Drop the parts back in — the joiner detects the sequence, flags missing pieces, decrypts and verifies the MD5 automatically.

Real downloads & reports

Individual parts, an all-in-one ZIP, JSON manifest, CSV report, reassembly instructions and a .sha256 checksum file.

What is a file splitter?

Why split a file?

Splitting unlocks transfers and storage that a single large file can’t do. The most common reasons:

Beat size limits — fit Gmail, WhatsApp, Discord, Telegram and other per-file caps.
Transfer reliably — if one part fails, re-send just that part, not the whole file.
Store on small media — spread parts across USB sticks, DVDs or FAT32 drives.
Share privately — split (and encrypt) locally instead of uploading to a cloud splitter.
Parallelise — upload or download parts at the same time to go faster.
Archive & back up — break huge backups into verifiable, manageable pieces.

Split a file in 4 steps

Add your file

Choose how to split

Add integrity & security

Split & download

Whole file vs split parts

Keeping a file whole is simplest when it fits your channel; splitting wins the moment size, reliability, storage or privacy gets in the way. The table compares the two where it matters.

Scenario	Whole file	Split parts
Fits size limits (email/chat)	Often too big to send	Sized to fit any limit
Transfer reliability	One failure restarts everything	Re-send only the failed part
Storage on small media	May exceed FAT32 / disk limits	Spread across disks, under limits
Privacy	Cloud splitters upload it	Split locally — never uploaded
Integrity	No built-in verification	Per-chunk SHA-256 + MD5 verify
Security	Plain bytes	Optional AES-256 per chunk
Reassembly	N/A	Verified one-click join

What you can split

Splitting is byte-level, so it works on any file — these are the types people split most.

Large Videos

Disk Images (ISO)

Archives (ZIP/RAR/7z)

VM Disks (VMDK/VDI)

Database Backups

Installers & Games

Design Files (PSD/AI)

Datasets & Logs

PDF Documents

Any Binary File

Best file splitter settings

Different goals call for different settings. These give the cleanest result on the first try.

Email a large file

Platform mode → Gmail/Outlook · MD5 + SHA-256 · download as ZIP

Share on Discord / chat

Platform mode → Discord 8 MB (or Nitro 100 MB) · individual parts

Confidential transfer

Size mode · AES-256 encryption · strong generated password · SHA-256

Store on a FAT32 drive

Size mode → 2 GB chunks (under the 4 GB limit) · keep the manifest

Resilient cloud upload

Size mode → 100 MB chunks · per-chunk SHA-256 · re-send failed parts

Split a PDF report

PDF by pages → 10 pages each · standalone PDFs (no rejoin needed)

Integrity, encryption & verified rejoining

Privacy, security & data handling

File Splitter API & large-file pipelines

Free

$0/mo

100 split/join jobs / mo
Byte & PDF splitting
Integrity hashes
Community support

Start free

Popular

Pro

$19/mo

10,000 jobs / mo
AES encryption + manifests
Resumable chunked uploads
Webhooks & async jobs

Go Pro

Business

$69/mo

100,000 jobs / mo
Format-aware chunking
Storage connectors
Team accounts & API keys

Choose Business

Enterprise

Custom

Unlimited volume & SLA
Scheduled splitting & backups
Data-validation rules
Dedicated support

Contact sales

File Splitter

Drag & drop a file to split

Why this is the best free file splitter

5 ways to split

100% private

Integrity built in

AES-256 encryption

Verified joiner

Real downloads & reports

What is a file splitter?

Why split a file?

Split a file in 4 steps

Add your file

Choose how to split

Add integrity & security

Split & download

Whole file vs split parts

What you can split

Best file splitter settings

Email a large file

Share on Discord / chat

Confidential transfer

Store on a FAT32 drive

Resilient cloud upload

Split a PDF report

Integrity, encryption & verified rejoining

Privacy, security & data handling

File Splitter API & large-file pipelines

Free

Pro

Business

Enterprise

Frequently Asked Questions

Troubleshooting guide

File Splitter

Drag & drop a file to split

Why this is the best free file splitter

5 ways to split

100% private

Integrity built in

AES-256 encryption

Verified joiner

Real downloads & reports

What is a file splitter?

Why split a file?

Split a file in 4 steps

Add your file

Choose how to split

Add integrity & security

Split & download

Whole file vs split parts

What you can split

Best file splitter settings

Email a large file

Share on Discord / chat

Confidential transfer

Store on a FAT32 drive

Resilient cloud upload

Split a PDF report

Integrity, encryption & verified rejoining

Privacy, security & data handling

File Splitter API & large-file pipelines

Free

Pro

Business

Enterprise

Frequently Asked Questions

Troubleshooting guide