Bulk File Renamer

Why this is the best free bulk file renamer

A bulk file renamer applies one consistent naming rule to many files at once instead of renaming them by hand. You define a rule - add a prefix, replace a word, number the files, build a name from metadata or a template - and the tool rewrites every filename the same way in a single pass.

This renamer runs entirely in your browser. You drop in files or a folder, it analyses them, you configure a rule, you preview every change, and then you download the renamed files (individually or as a ZIP, optionally organised into folders). Because the work happens locally with the File and Blob APIs, your files - and their metadata - never leave your device.

• Rename hundreds or thousands of files with one rule
• Add, remove, replace and insert text anywhere in the name
• Convert case: lower, UPPER, Title, camelCase, snake_case, kebab-case
• Number files automatically with custom padding and steps
• Build names from EXIF, ID3, PDF and Office metadata
• Preview every change with conflict and validation checks

Inconsistent filenames are slow to search, hard to sort and easy to lose. Camera dumps full of IMG_0001.jpg, downloads called document(3).pdf, and exports with mismatched casing all make folders harder to work with. Bulk renaming fixes the whole set at once so names are predictable, sortable and meaningful.

It also prepares data for the systems that consume it. Machine-learning datasets need uniform, index-based names. Media libraries sort correctly only when track and date fields are in the filename. Content pipelines and CDNs want web-safe, lower-case, hyphenated slugs. A renamer turns a messy folder into something a person - or a script - can rely on.

• Organise files and make them searchable
• Fix inconsistent naming conventions in one step
• Prepare clean, indexed datasets for ML and analytics
• Manage photo, music and video libraries
• Produce web-safe slugs for the web and CDNs
• Standardise shared-drive naming across a team

How to rename files in bulk in 4 steps

Six modes cover every workflow. Simple replaces the whole filename with one name plus an automatic counter. Pattern keeps the current name and layers on add/remove/replace/case rules. Sequential numbers files with padding and a chosen step. Metadata builds names from embedded fields like camera model, date taken, artist or document title. Template composes any name from dynamic tokens. Smart derives a name from the file content itself - OCR text from an image, or the first meaningful words of a document.

You can combine ideas freely: a Template like {date}_{filename}-{counter} mixes a date, the original name and a padded counter, then a case rule turns the result into a clean slug. Every mode feeds the same live preview, so you always see exactly what each file will be called before you commit.

Metadata renaming reads the real information embedded in your files. For photos, the tool parses EXIF to pull camera make and model, the date a shot was taken, ISO, lens and GPS. For audio, it reads ID3 tags for artist, album, track, genre, year and composer. For PDFs it reads the author, title, subject, keywords, creation date and page count, and for Office documents it reads the same core properties from the document package.

That means a folder of IMG_*.jpg can become Canon-R5_2026-06-23_001.jpg, and a music dump can become Artist-Album-01.mp3 - automatically, with no manual lookup. All parsing happens in the browser by reading the file bytes, so nothing is uploaded.

• Images: camera, lens, ISO, date taken, GPS, resolution
• Audio: artist, album, track, genre, year, composer
• Documents: author, title, subject, keywords, page count, dates
• Video: duration and resolution from the media itself

Smart mode names files from what is actually inside them. For images, optional OCR (powered by tesseract.js, in 13 languages) reads any text in the picture and turns the key words into a filename. For text, markdown, CSV, code and Word documents, it reads the first meaningful words of the content and builds a slug from them.

We deliberately do not fake "AI object detection" or send your files to a remote model. Smart naming is built on verifiable, on-device extraction - OCR text and real document content - so the names it suggests come from information you can see in the file. You always review the result in the preview before renaming.

Tokens are placeholders wrapped in braces that expand per file. {filename} is the original base name, {ext} the extension, {counter} a padded sequence number, {date} and {time} the current date and time, and {year}/{month}/{day} their parts. Metadata tokens like {camera}, {datetaken}, {artist}, {album}, {track}, {author}, {title} and {pagecount} pull from embedded fields, while {filesize}, {filetype}, {foldername}, {random} and {uuid} cover the rest.

Append a number to pad - {counter:4} gives 0007 - and combine tokens with literal text: {date}_{title}-{counter} becomes 2026-06-23_Quarterly-Report-001. Missing values collapse to nothing rather than leaving a literal {token} in the name, so partial metadata never breaks a batch.

Manual renaming vs a bulk renamer

Supported file types

Renaming works on any file. Metadata reading is tuned for the formats below.

Best naming conventions

Good filenames are consistent, sortable and descriptive. These battle-tested patterns work for each kind of content.

Recommended settings by scenario

When a rule would produce the same name for two files, that is a conflict. The renamer detects collisions across the whole batch (including the folder a file is sorted into) and lets you choose how to resolve them: append a counter so each file gets a unique name, skip the file and keep its original name, allow the overwrite, or flag it as an error to fix manually.

The analysis panel also surfaces duplicate names, invalid names, overly long names and unsupported characters in the original set, so you can see problems before you even pick a rule.

Windows, macOS and Linux disagree about what makes a legal filename. Windows forbids the characters < > : " / \ | ? * , reserves device names like CON and NUL, and trims trailing dots and spaces. macOS and Linux are more permissive but still trip over leading dots, slashes and very long paths. The renamer validates every proposed name against all three and flags errors and warnings inline.

It checks for illegal and control characters, reserved names, zero-width and bidirectional characters, byte length against the 255-byte filename limit, and patterns that hit the Windows 260-character path limit - so the names you generate work wherever the files end up.

Renaming and organising go together. As it renames, the tool can sort files into folders inside the downloaded ZIP - by type (Photos, Documents, Videos...), by extension, by month (YYYY-MM from the file date), by first letter, or by any token you choose. A camera dump can come back as Photos/2026-06/Canon-R5_2026-06-23_001.jpg without any manual filing.

If you uploaded a folder tree and leave organisation off, the original structure is preserved in the ZIP, so you can rename in place without flattening your hierarchy.

Every rename you apply is recorded as a snapshot. You can undo the last change, step back through the history, or restore the original names entirely - all before you download, so you never lose the source filenames. Because nothing is written to disk until you download, the original files on your device are never modified by the tool itself.

The renamer is built for big batches. File analysis and name computation are incremental, the preview virtualises long lists, and metadata extraction reads only the bytes it needs (for example the EXIF header of a photo rather than the whole image). ZIP packaging streams files in without re-compressing already-compressed media, keeping memory use low even with tens of thousands of files.

For very large sets, you can exclude files from the batch, apply a page-range style selection, and process in passes. Everything runs on your CPU in the browser, so throughput scales with your machine rather than a server queue.

This tool is private by design. Files are read with the browser File API and processed in memory; they are never uploaded to a server, so there is nothing to leak, cache or delete. Metadata parsing, OCR and ZIP creation all happen locally. When you close the tab, the files and everything derived from them are gone.

That makes it safe for sensitive material - financial documents, client work, personal photos and confidential datasets - where uploading to a cloud renamer would be unacceptable. There are no accounts, watermarks or hidden processing.

Bulk Rename API and document intelligence

For automated pipelines, the same naming engine is available as an API for renaming, metadata extraction, AI naming and batch processing with async jobs, webhooks, API keys, team accounts and usage analytics. Use it to standardise uploads at ingest, name assets in a DAM, or normalise datasets at scale. Pricing scales from a free tier to enterprise.

Frequently Asked Questions