xterm.js

Tested Software version 6.1.0-beta.213 on Linux. The xterm.js variant tested is the one shipped with Visual Studio Code’s integrated terminal. The homepage URL of this terminal is https://code.visualstudio.com/docs/terminal/basics. Full results available at ucs-detect repository path data/vscodeterminal.yaml.

xterm.js is a terminal multiplexer. These tests were executed in host terminal :ref:`ghostty. The homepage URL of this host terminal is https://ghostty.org/.

Score Breakdown

Detailed breakdown of how scores are calculated for xterm.js:

#

Score Type

Raw Score

Final Scaled Score

1

WIDE

34.00%

6.7%

2

NARROW

0.00%

0.0%

3

ZWJ

0.69%

0.7%

4

LANG

92.35%

92.3%

5

VS16

50.00%

50.0%

6

VS15

0.00%

(excluded)

7

SRI

0.00%

0.0%

8

SFZ

100.00%

100.0%

9

RI

100.00%

100.0%

10

FEAT

53.12%

56.7%

11

Graphics

0%

0.0%

12

Resources

N/A

N/A

Score Comparison Plot:

The following plot shows how this terminal’s scores compare to all other terminals tested.

../_images/xtermjs_scores_scaled.png

Scaled scores comparison across all metrics (normalized 0-100%)

Final Scaled Score Calculation:

  • Raw Final Score: 39.65% (weighted average: WIDE + NARROW + ZWJ + LANG + VS16 + 0.33 * SRI + 0.33 * SFZ + RI + CAP + 0.5 * GFX + 0.5 * RSC) the categorized ‘average’ absolute support level of this terminal.

    Note

    RSC (Resources) is a composite CPU, memory, and runtime score. RSC is weighted at 0.5 (half as powerful as other metrics). FEAT (Features) is the fraction of notable features supported. GFX (Graphics) scores 100% for modern protocols (iTerm2, Kitty), 50% for legacy only (Sixel, ReGIS), 0% for none.

  • Final Scaled Score: 9.4% (normalized across all terminals tested). Final Scaled scores are normalized (0-100%) relative to all terminals tested

WIDE Score Details:

Wide character support calculation:

  • Total successful codepoints: 188

  • Total codepoints tested: 553

  • Formula: 188 / 553

  • Result: 34.00%

NARROW Score Details:

No NARROW character support detected.

ZWJ Score Details:

Emoji ZWJ (Zero-Width Joiner) support calculation:

  • Total successful sequences: 10

  • Total sequences tested: 1445

  • Formula: 10 / 1445

  • Result: 0.69%

VS16 Score Details:

Variation Selector-16 support calculation:

  • Errors: 213 of 426 codepoints tested

  • Success rate: 50.0%

  • Formula: 50.0 / 100

  • Result: 50.00%

VS15 Score Details (excluded from final score):

Variation Selector-15 support calculation:

  • Errors: 158 of 158 codepoints tested

  • Success rate: 0.0%

  • Formula: 0.0 / 100

  • Result: 0.00%

SRI Score Details:

Standalone Regional Indicator support calculation:

  • Total successful codepoints: 0

  • Total codepoints tested: 26

  • Formula: 0 / 26

  • Result: 0.00%

SFZ Score Details:

Standalone Fitzpatrick skin tone modifier support calculation:

  • Total successful codepoints: 5

  • Total codepoints tested: 5

  • Formula: 5 / 5

  • Result: 100.00%

RI Score Details:

Regional Indicator flag sequence support calculation:

  • Total successful sequences: 262

  • Total sequences tested: 262

  • Formula: 262 / 262

  • Result: 100.00%

Features Score Details:

Notable terminal features (8.5 / 16):

Raw score: 53.12%

Graphics Score Details:

Graphics protocol support (0%):

  • Sixel: no

  • ReGIS: no

  • iTerm2: no

  • Kitty: no

Scoring: 100% for modern (iTerm2/Kitty), 50% for legacy only (Sixel/ReGIS), 0% for none

Resource Score Details:

Resource profiling data not available.

LANG Score Details (Geometric Mean):

Geometric mean calculation:

  • Formula: (p₁ × p₂ × … × pₙ)^(1/n) where n = 85 languages

  • About geometric mean

  • Result: 92.35%

Wide character support

Wide character support of xterm.js is 34.0% (365 errors of 553 codepoints tested).

Sequence of a WIDE character, from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0001D34F

‘\U0001d34f’

So

2

TETRAGRAM FOR CLOSURE

Total codepoints: 1

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x9d\x8d\x8f|\\n12|\\n"
𝍏|
12|

  • See Line 42314 of ucs_wide.txt for this sequence in the example file.

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 1.

Narrow character support

Narrow character results for xterm.js are not available.

Emoji ZWJ support

Compatibility of xterm.js with the Unicode Emoji ZWJ sequence table is 0.7% (1435 errors of 1445 sequences tested).

Sequence of an Emoji ZWJ Sequence, from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0001F482

‘\U0001f482’

So

2

GUARDSMAN

2

U+0001F3FE

‘\U0001f3fe’

Sk

2

EMOJI MODIFIER FITZPATRICK TYPE-5

3

U+200D

‘\u200d’

Cf

0

ZERO WIDTH JOINER

4

U+2642

‘\u2642’

So

1

MALE SIGN

5

U+FE0F

‘\ufe0f’

Mn

0

VARIATION SELECTOR-16

Total codepoints: 5

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x9f\x92\x82\xf0\x9f\x8f\xbe\xe2\x80\x8d\xe2\x99\x82\xef\xb8\x8f|\\n12|\\n"
💂🏾‍♂️|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 5.

Variation Selector-16 support

Emoji VS-16 results for xterm.js is 213 errors out of 426 total codepoints tested, 50.0% success. Sequence of a NARROW Emoji made WIDE by Variation Selector-16, from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+2733

‘\u2733’

So

1

EIGHT SPOKED ASTERISK

2

U+FE0F

‘\ufe0f’

Mn

0

VARIATION SELECTOR-16

Total codepoints: 2

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe2\x9c\xb3\xef\xb8\x8f|\\n12|\\n"
✳️|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 1.

Variation Selector-15 support

Emoji VS-15 results for xterm.js is 158 errors out of 158 total codepoints tested, 0.0% success. Sequence of a WIDE Emoji made NARROW by Variation Selector-15, from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0001F3AE

‘\U0001f3ae’

So

2

VIDEO GAME

2

U+FE0E

‘\ufe0e’

Mn

0

VARIATION SELECTOR-15

Total codepoints: 2

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x9f\x8e\xae\xef\xb8\x8e|\\n1|\\n"
🎮︎|
1|

  • python wcwidth.wcswidth() measures width 1, while xterm.js measures width 2.

Standalone Regional Indicator support

Standalone Regional Indicator support of xterm.js is 0.0% (26 errors of 26 codepoints tested).

Sequence of a standalone Regional Indicator, from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0001F1F3

‘\U0001f1f3’

So

2

REGIONAL INDICATOR SYMBOL LETTER N

Total codepoints: 1

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x9f\x87\xb3|\\n12|\\n"
🇳|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 1.

Standalone Fitzpatrick modifier support

Standalone Fitzpatrick skin tone modifier support of xterm.js is 100.0% (0 errors of 5 codepoints tested).

Regional Indicator flag sequence support

Regional Indicator flag sequence support of xterm.js is 100.0% (0 errors of 262 sequences tested).

Graphics Protocol Support

xterm.js does not report support for any graphics protocols.

Note: Must be enabled with "terminal.integrated.enableImages": true.

Detection Methods:

  • Sixel and ReGIS: Detected via the Device Attributes (DA1) query CSI c (\x1b[c). Extension code 4 indicates Sixel support, 3 ReGIS.

  • Kitty graphics: Detected by sending a Kitty graphics query and checking for an OK response.

  • iTerm2 inline images: Detected via the iTerm2 capabilities query OSC 1337 ; Capabilities.

Device Attributes Response:

  • Extensions reported: 2

  • Sixel indicator (4): not present

  • ReGIS indicator (3): not present

Language Support

The following 65 languages were tested with 100% success:

Aja, Amarakaeri, Arabic, Standard, Assyrian Neo-Aramaic, Baatonum, Bamun, Belanda Viri, Bora, Catalan (2), Chickasaw, Chinantec, Chiltepec, Dagaare, Southern, Dari, Dendi, Dinka, Northeastern, Dzongkha, Evenki, Farsi, Western, Fon, French (Welche), Fur, Ga, Gen, Gilyak, Gumuz, Kabyle, Lamnso’, Lao, Lingala (tones), Maldivian, Maori (2), Mazahua Central, Mòoré, Nanai, Navajo, Orok, Otomi, Mezquital, Panjabi, Eastern, Panjabi, Western, Pashto, Northern, Picard, Pular (Adlam), Secoya, Seraiki, Shan, Shipibo-Conibo, Sinhala, Siona, South Azerbaijani, Tagalog (Tagalog), Tai Dam, Tamazight, Central Atlas, Tamil, Tem, Thai, Thai (2), Tibetan, Central, Ticuna, Uduk, Urdu, Urdu (2), Vietnamese, Yaneshaʼ, Yiddish, Eastern, Yoruba.

The following 20 languages are not fully supported:

lang

n_errors

n_total

pct_success

Javanese (Javanese)

321

488

34.2%

Tamang, Eastern

6

11

45.5%

Sanskrit

81

155

47.7%

Marathi

46

103

55.3%

Malayalam

139

382

63.6%

Hindi

56

164

65.9%

Magahi

7

22

68.2%

Nepali

22

71

69.0%

Maithili

19

66

71.2%

Bengali

96

335

71.3%

Sanskrit (Grantha)

61

237

74.3%

Khmer, Central

90

390

76.9%

Gujarati

50

290

82.8%

Bhojpuri

41

252

83.7%

Telugu

42

335

87.5%

Kannada

14

236

94.1%

Chakma

13

225

94.2%

Burmese

10

223

95.5%

Mon

7

208

96.6%

Khün

4

354

98.9%

Javanese (Javanese)

Sequence of language Javanese (Javanese) from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+A98F

‘\ua98f’

Lo

1

JAVANESE LETTER KA

2

U+A9BA

‘\ua9ba’

Mc

0

JAVANESE VOWEL SIGN TALING

3

U+A9B4

‘\ua9b4’

Mc

0

JAVANESE VOWEL SIGN TARUNG

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xea\xa6\x8f\xea\xa6\xba\xea\xa6\xb4|\\n12|\\n"
ꦏꦺꦴ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Tamang, Eastern

Sequence of language Tamang, Eastern from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

4

U+094B

‘\u094b’

Mc

0

DEVANAGARI VOWEL SIGN O

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\x95\xe0\xa5\x8b|\\n12|\\n"
क्को|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Sanskrit

Sequence of language Sanskrit from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

4

U+093E

‘\u093e’

Mc

0

DEVANAGARI VOWEL SIGN AA

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\x95\xe0\xa4\xbe|\\n12|\\n"
क्का|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Marathi

Sequence of language Marathi from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

4

U+093E

‘\u093e’

Mc

0

DEVANAGARI VOWEL SIGN AA

5

U+0902

‘\u0902’

Mn

0

DEVANAGARI SIGN ANUSVARA

Total codepoints: 5

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\x95\xe0\xa4\xbe\xe0\xa4\x82|\\n12|\\n"
क्कां|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Malayalam

Sequence of language Malayalam from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0D15

‘\u0d15’

Lo

1

MALAYALAM LETTER KA

2

U+0D4D

‘\u0d4d’

Mn

0

MALAYALAM SIGN VIRAMA

3

U+0D15

‘\u0d15’

Lo

1

MALAYALAM LETTER KA

4

U+0D3E

‘\u0d3e’

Mc

0

MALAYALAM VOWEL SIGN AA

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xb4\x95\xe0\xb5\x8d\xe0\xb4\x95\xe0\xb4\xbe|\\n12|\\n"
ക്കാ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Hindi

Sequence of language Hindi from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0928

‘\u0928’

Lo

1

DEVANAGARI LETTER NA

4

U+093F

‘\u093f’

Mc

0

DEVANAGARI VOWEL SIGN I

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xa8\xe0\xa4\xbf|\\n12|\\n"
क्नि|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Magahi

Sequence of language Magahi from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0937

‘\u0937’

Lo

1

DEVANAGARI LETTER SSA

4

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

5

U+0923

‘\u0923’

Lo

1

DEVANAGARI LETTER NNA

Total codepoints: 5

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xb7\xe0\xa5\x8d\xe0\xa4\xa3|\\n12|\\n"
क्ष्ण|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Nepali

Sequence of language Nepali from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0924

‘\u0924’

Lo

1

DEVANAGARI LETTER TA

4

U+093E

‘\u093e’

Mc

0

DEVANAGARI VOWEL SIGN AA

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xa4\xe0\xa4\xbe|\\n12|\\n"
क्ता|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Maithili

Sequence of language Maithili from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0937

‘\u0937’

Lo

1

DEVANAGARI LETTER SSA

4

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

5

U+092F

‘\u092f’

Lo

1

DEVANAGARI LETTER YA

Total codepoints: 5

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xb7\xe0\xa5\x8d\xe0\xa4\xaf|\\n12|\\n"
क्ष्य|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Bengali

Sequence of language Bengali from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0995

‘\u0995’

Lo

1

BENGALI LETTER KA

2

U+09BF

‘\u09bf’

Mc

0

BENGALI VOWEL SIGN I

3

U+0982

‘\u0982’

Mc

0

BENGALI SIGN ANUSVARA

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa6\x95\xe0\xa6\xbf\xe0\xa6\x82|\\n12|\\n"
কিং|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Sanskrit (Grantha)

Sequence of language Sanskrit (Grantha) from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+00011315

‘\U00011315’

Lo

1

GRANTHA LETTER KA

2

U+0001133E

‘\U0001133e’

Mc

0

GRANTHA VOWEL SIGN AA

3

U+00011302

‘\U00011302’

Mc

0

GRANTHA SIGN ANUSVARA

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x91\x8c\x95\xf0\x91\x8c\xbe\xf0\x91\x8c\x82|\\n12|\\n"
𑌕𑌾𑌂|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Khmer, Central

Sequence of language Khmer, Central from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+1780

‘\u1780’

Lo

1

KHMER LETTER KA

2

U+17D2

‘\u17d2’

Mn

0

KHMER SIGN COENG

3

U+178A

‘\u178a’

Lo

1

KHMER LETTER DA

4

U+17C5

‘\u17c5’

Mc

0

KHMER VOWEL SIGN AU

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe1\x9e\x80\xe1\x9f\x92\xe1\x9e\x8a\xe1\x9f\x85|\\n12|\\n"
ក្ដៅ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Gujarati

Sequence of language Gujarati from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0A95

‘\u0a95’

Lo

1

GUJARATI LETTER KA

2

U+0ACD

‘\u0acd’

Mn

0

GUJARATI SIGN VIRAMA

3

U+0A95

‘\u0a95’

Lo

1

GUJARATI LETTER KA

4

U+0ABE

‘\u0abe’

Mc

0

GUJARATI VOWEL SIGN AA

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xaa\x95\xe0\xab\x8d\xe0\xaa\x95\xe0\xaa\xbe|\\n12|\\n"
ક્કા|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Bhojpuri

Sequence of language Bhojpuri from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0915

‘\u0915’

Lo

1

DEVANAGARI LETTER KA

2

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

3

U+0918

‘\u0918’

Lo

1

DEVANAGARI LETTER GHA

4

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

5

U+0918

‘\u0918’

Lo

1

DEVANAGARI LETTER GHA

6

U+093F

‘\u093f’

Mc

0

DEVANAGARI VOWEL SIGN I

7

U+094D

‘\u094d’

Mn

0

DEVANAGARI SIGN VIRAMA

Total codepoints: 7

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\x98\xe0\xa5\x8d\xe0\xa4\x98\xe0\xa4\xbf\xe0\xa5\x8d|\\n12|\\n"
क्घ्घि्|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 4.

Telugu

Sequence of language Telugu from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0C15

‘\u0c15’

Lo

1

TELUGU LETTER KA

2

U+0C41

‘\u0c41’

Mc

0

TELUGU VOWEL SIGN U

3

U+0C02

‘\u0c02’

Mc

0

TELUGU SIGN ANUSVARA

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xb0\x95\xe0\xb1\x81\xe0\xb0\x82|\\n12|\\n"
కుం|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Kannada

Sequence of language Kannada from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+0C95

‘\u0c95’

Lo

1

KANNADA LETTER KA

2

U+0CBE

‘\u0cbe’

Mc

0

KANNADA VOWEL SIGN AA

3

U+0C82

‘\u0c82’

Mc

0

KANNADA SIGN ANUSVARA

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe0\xb2\x95\xe0\xb2\xbe\xe0\xb2\x82|\\n12|\\n"
ಕಾಂ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Chakma

Sequence of language Chakma from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+00011107

‘\U00011107’

Lo

1

CHAKMA LETTER KAA

2

U+00011133

‘\U00011133’

Mn

0

CHAKMA VIRAMA

3

U+00011120

‘\U00011120’

Lo

1

CHAKMA LETTER YYAA

4

U+0001112C

‘\U0001112c’

Mc

0

CHAKMA VOWEL SIGN E

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xf0\x91\x84\x87\xf0\x91\x84\xb3\xf0\x91\x84\xa0\xf0\x91\x84\xac|\\n12|\\n"
𑄇𑄳𑄠𑄬|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Burmese

Sequence of language Burmese from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+1000

‘\u1000’

Lo

1

MYANMAR LETTER KA

2

U+103B

‘\u103b’

Mc

0

MYANMAR CONSONANT SIGN MEDIAL YA

3

U+1031

‘\u1031’

Mc

0

MYANMAR VOWEL SIGN E

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe1\x80\x80\xe1\x80\xbb\xe1\x80\xb1|\\n12|\\n"
ကျေ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Mon

Sequence of language Mon from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+1007

‘\u1007’

Lo

1

MYANMAR LETTER JA

2

U+103C

‘\u103c’

Mc

0

MYANMAR CONSONANT SIGN MEDIAL RA

3

U+1031

‘\u1031’

Mc

0

MYANMAR VOWEL SIGN E

Total codepoints: 3

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe1\x80\x87\xe1\x80\xbc\xe1\x80\xb1|\\n12|\\n"
ဇြေ|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

Khün

Sequence of language Khün from midpoint of alignment failure records:

#

Codepoint

Python

Category

wcwidth

Name

1

U+1A23

‘\u1a23’

Lo

1

TAI THAM LETTER LOW KA

2

U+1A55

‘\u1a55’

Mc

0

TAI THAM CONSONANT SIGN MEDIAL RA

3

U+1A6E

‘\u1a6e’

Mc

0

TAI THAM VOWEL SIGN E

4

U+1A60

‘\u1a60’

Mn

0

TAI THAM SIGN SAKOT

Total codepoints: 4

  • Shell test using printf(1), '|' should align in output:

    $ printf "\xe1\xa8\xa3\xe1\xa9\x95\xe1\xa9\xae\xe1\xa9\xa0|\\n12|\\n"
ᨣᩕᩮ᩠|
12|

  • python wcwidth.wcswidth() measures width 2, while xterm.js measures width 3.

DEC Private Modes Support

DEC private modes results for xterm.js: 4 changeable modes of 4 supported out of 8 total modes tested (50.0% support, 50.0% changeable).

Complete list of DEC private modes tested:

Mode

Name

Description

Supported

Changeable

Enabled

1004

FOCUS_IN_OUT_EVENTS

Send FocusIn/FocusOut events

Yes

Yes

No

1006

MOUSE_EXTENDED_SGR

Enable SGR Mouse Mode

Yes

Yes

No

2004

BRACKETED_PASTE

Set bracketed paste mode

Yes

Yes

No

2026

SYNCHRONIZED_OUTPUT

Synchronized Output

Yes

Yes

No

2027

GRAPHEME_CLUSTERING

Grapheme Clustering

No

No

No

2031

COLOR_PALETTE_UPDATES

Color palette updates

No

No

No

2048

IN_BAND_WINDOW_RESIZE

In-Band Window Resize Notifications

No

No

No

5522

BRACKETED_PASTE_MIME

Bracketed Paste MIME

No

No

No

Summary: 4 changeable, 4 not changeable.

Kitty Keyboard Protocol

xterm.js supports the Kitty keyboard protocol.

#

Flag

Key

State

1

Disambiguate escape codes

disambiguate

No

2

Report event types

report_events

No

3

Report alternate keys

report_alternates

No

4

Report all keys as escape codes

report_all_keys

No

5

Report associated text

report_text

No

Detection is performed by sending CSI ? u to query the current progressive enhancement flags. A terminal that supports this protocol responds with the active flags value.

XTGETTCAP (Terminfo Capabilities)

xterm.js does not support the XTGETTCAP sequence.

Text Sizing Protocol (OSC 66)

xterm.js does not support the Text Sizing protocol.

Truecolor Support

xterm.js supports 24-bit truecolor, detectable via:

  • XTGETTCAP (RGB capability): no

  • DECRQSS (truecolor probe): no

  • COLORTERM: yes (truecolor)

Warning

COLORTERM is an environment variable, not a terminal query. It is not forwarded over SSH without SendEnv / AcceptEnv configuration, so detection via COLORTERM alone may be unreliable on remote hosts.

OSC 52 Clipboard Support

xterm.js does not advertise OSC 52 clipboard support via DA1 extension 52 or XTGETTCAP Ms.

  • DA1 extension 52: no

  • XTGETTCAP Ms: no

Terminal Identification

xterm.js is identified as xterm.js version 6.1.0-beta.213 (detected via XTVERSION).

  • XTVERSION (raw): xterm.js(6.1.0-beta.220)

  • XTVERSION: yes

  • XTGETTCAP TN: no

  • ENQ: no

  • TERM_PROGRAM: yes (vscode)

  • TERM: no (xterm-256color) (inherited from host terminal)

Reproduction

To reproduce these results for xterm.js, install and run ucs-detect with the following commands:

uvx ucs-detect --rerun data/vscodeterminal.yaml

Test Performance

Performance data for xterm.js is not available.