Online file viewers
Only viewers that are built and tested are listed here. The ones marked local never send your file anywhere.
Base64 Encoder & Decoder
Paste a Base64 string and the decoded result appears in the same tab: readable text when the bytes are valid UTF-8, a named image container or a byte report with a download when they are not. You can also open a .txt or .b64 file that holds the string instead of pasting it. Both alphabets are accepted — standard with + and /, URL-safe with - and _ — and the tool reports which one it saw. Spaces, tabs, line breaks, non-breaking spaces and a stray byte order mark are counted and ignored rather than decoded as data, and a data: URL prefix is stripped and reported with the media type it declares. Every rejection carries a stable code, and the validation errors that can point at a character — an invalid character, mixed alphabets, misplaced or excess padding, an impossible length, or a data: URL without the base64 marker — also give the exact index, line and column in the string as you pasted it; the size and empty-input refusals have no single character to blame, so they report the counts and the limit instead. The encoder runs the other way: text or bytes become Base64 in the standard or URL-safe alphabet, padded or unpadded, with the decoded byte length reported rather than the character count.
.txt · .b64CSV & TSV Viewer
Choose a .csv or .tsv file, or paste the text straight into the page, and the rows appear as a table with row and column counts. The delimiter is decided by the header row itself among comma, tab, semicolon and pipe, so a semicolon export from a European spreadsheet or a tab-separated file saved with a .csv name is still read correctly; you can also name the delimiter yourself instead of letting the header decide. Quoting follows RFC 4180: a comma inside quotes stays in its cell, a doubled quote collapses to one quote, and a line break inside quotes keeps the cell together instead of starting a new row. Long files are shown 500 rows at a time so scrolling stays responsive. Rows that carry more or fewer fields than the header are listed by row number rather than padded or dropped, and blank rows, mixed CRLF and LF line endings, stray text after a closing quote and a shortened preview each raise their own visible warning. Copy and download always return the complete source text — including a UTF-8 byte order mark if the file had one — not just the part on screen.
.csv · .tsvFile Hash & Checksum Verifier
Pick one file — or paste text — and the page reads it in 1 MB slices and hashes it locally. The full lowercase hexadecimal digest is shown together with the algorithm name and the exact number of bytes hashed, and it is never shortened, grouped or reformatted for display: a SHA-256 result is always the complete 64 characters. To verify a download, paste the value the publisher listed into the expected-checksum box; surrounding whitespace is trimmed and upper case is accepted, and the outcome is reported as match, mismatch, or invalid expected value — never as "almost the same". Large files show progress while they are read and the tab keeps responding, because the file is hashed slice by slice instead of being loaded whole. You can copy the digest on its own or as a checksum line that puts the digest in front of the file name, and download it as a .sha256, .sha384 or .sha512 text file. Every input is treated as an opaque byte stream: the extension is ignored and nothing is decoded as text, so installers, archives, disk images, photos and documents are all hashed the same way. Pasted text is the one exception — it is encoded as UTF-8 first, and the result records that.
.*JSON Viewer
JSON Viewer is a browser-local viewer for JSON and JSONL files that parses and formats them, shows the top-level structure, and reports syntax errors by line and column while leaving the original text unchanged.
.json · .jsonlText & Markdown Viewer
Open TXT, Markdown, and log files locally, switch between reading and source views, search the text, and count lines, words and characters.
.txt · .md · .markdown · .log